The stations I missed were Watford, Croxley and Amersham. I was at Harrow on the Hill for the last 3 trains, 1 each to each terminus, and I chose to finish at Chesham.
So, waking up at 02:45 with only a couple hours of sleep (I tried to get more, I just couldnt get to sleep!), Dad very kindly gave me a lift to Heathrow T4, leaving at 03:25, reaching the terminal at about 04:45, plenty of time to buy a ticket before the first tube, which myself and one other boarded. The first section, 4 to 123 to 5 to Baron's Court went very smoothly, and I ran/walked to Olympia, and was on a train about 06:15, much earlier than I had anticipated. Due to being 'ahead', after getting into Earl's Court, I did the irritating double back to West Kensington, which I had planned to do later in the day, before the Wimbledon branch. After this, I headed up to Edgware Road, after changing at High Street Kensington. Later in the day I was pleased to have done this section early, as this was the only part of the tube to be suspended all day. Good service was resumed later though. From Edgware Road, I headed to Hammersmith, then did the Richmond Branch, double backing, before heading to Ealing Common, transfering to the Central Line and taking it all the way to Bank. From Bank, I headed to Kings Cross, then getting a Piccadilly Line train to Arnos Grove, and then Cockfosters.
At Cockfosters, I panicked about the bus connection I had to make, and wasted time. I looked for the loo, but it was a pay for loo, so I decided not to bother. I went out and back in the station, before backtracking to Oakwood. Time wasted. At Oakwood, I found the bus stop, but due to temporary traffic lights, it took a hideously long time for a 307 to arrive. When it did, 2 came at once. I got on the first one, and the second one later overtook it and got to High Barnet first.

High Barnet exterior is really pretty for a tube station! Made a mistake at High Barnet, and didn't board the first train that left. I dont know if there were first train indicators there, if there were, I didn't notice them Boarded a train heading to East Finchley, alighting at the disastrous Finchley Central- 11 mins for a Mill Hill East train. At least I had time to use a loo! Headed down to King's Cross again, this time heading to Walthamstow Central. I was supposed to meet Mum here, but the moment I was there, mum was overground to get signal to check for messages from me. She recieved the text 'ill be there at 11:30' text.. at 11:30, and missed me. Got on a train that terminated at Seven Sisters. (this is a pattern!). At Walthamstow, my phone didn't want to give me walking directions to
Queen's Road, so I doubled back to Blackhorse Road to get an overground to Leytonstone High Road. Again, wasting time at Walthamstow and a fairly long wait for an overground train at Blackhorse Road meant I was behind even more. Out of Leytonstone High Road, as it was right there, I hopped on a 257 bus, though this probably didn't save any time. At Leytonstone, I had a choice. The next 2 trains were heading to Debden (pattern continues) or, iirc, Newbury Park. I took the one to Debden. Obviously, onto Epping. Once I got back into Woodford, a Hainault train was there on the platform. It had departed by the time I crossed the bridge. 15 minutes later, I boarded the next Hainault train, which took me to Liverpool Street. From there, I boarded the first train, a Met train to Aldgate, the first S stock I have used. Circle line to Tower Hill, District line to Upminster. At Upminster, I watched a c2c train leave to West Ham, 11 mins to the next one.
At West Ham, I met up with my mum, my sister and my sister's friend, the only time I did so. They supplied me with a back up mobile (Incredibly useful, my battery was running out!), some crisps, a fanta, a pasty and an iced bun, from Greggs.

After Mum corrected my mistake in terms of the platform I should be on, the 3 rode with me to Waterloo. At Waterloo, Went to Elephant and Castle, Oval, Bank--->Monument, and immediately hopped on a direct train to Wimbledon, which pleased me greatly. At Wimbledon, hopped straight on a 93 bus, which took me straight to Morden. Stress free! At Morden, to Stockwell, to Brixton, to Green Park, completely hitch free. One of those stops, don't recall which, was my closest to missing a train, as I hopped on while the beeping was sounding.
Now, the most intense part.
During rush hour, I dashed from Green Park, to Knightsbridge, back to Piccadilly Circus, to Charing Cross, to Leicester Square, to King's Cross St Pancras, to Barbican, to Baker Street, to Oxford Circus, to Tottenham Court Road, to Edgware, mainly due to poor route planning!
At Edgware, quite a long wait for a bus to Stanmore, I arrived to see 2 142 buses leaving the bus station, presumably 1 for each direction. I lost my pencil around this point!

At Stanmore, iirc, I boarded the first train out (hooray!), and was a really bumpy ride to Baker Street. I nearly forgot to exit the train! lol. At Baker Street, boarded the Bakerloo to Queen's Park. Waited a while for the next train at Queens Park, where the overhead dot matrix sign decided to display an IP address rather than information on the next train! At Harrow and Wealdstone, some helpful people told me I had exited the station the wrong way for buses. Found the bus stop, I planned to get an H10 bus to Northwick Park, but there was no sign of one on the arrivals board, so I got a 340 to Harrow on the Hill instead. While waiting for the bus, I hopped into the opposite 'Xpress' convenience store and bought a 49 pence can of Rubicon Mango drink. The only money I spent all day (excluding the ticket)!
Once at Harrow-on-the-hill, I double backed to Preston Road, before heading to Rayners Lane. At this point I was worried about how late it was getting. I needed to organise the location where dad would pick me up an hour in advance, and I wasn't sure what i'd be able to get done in the time I had left. At this point, I communicated a great deal with my mum, who was now back home. At North Ealing, I alighted and made a transfer, on foot, to Hanger Lane, after a discussion with more helpful people, advising me it was only an 8-10 minute walk. The bus just beat me, but at least I didn't have to worry about finding the bus stop, which wasn't apparant. Also, I wasn't risking a long wait for the bus. At Hanger Lane, up to West Ruislip, where a comedy of errors occurred. On advice from Mum, who had the journey planner up at home, I tried to catch the eastbound 11:30 U1 to Ruislip. I JUST missed it. I should have jumped the fence rather than running round it! lol. Again, on mum's advice, I waited for the 23:44 westbound U1 to Uxbridge. I caught the bus, intending to ride it to Uxbridge. In a moment of madness, I got Uxbridge and Ickenham mixed up, and asking locals 'Which stop for Ickenham station' they said "This one!, Take a left, and then right!" and in no time, I was there, shocked at the fact I had just waited 15 minutes for a bus which I took for one stop. >_> Anyway, while waiting at the bus stop, mum informed me of the last trains from HarrowOTH, ensuring I was fine to finish at Chesham. Once at Uxbridge, I boarded the Met to HarrowOTH, it confused me, that despite being on track by 2 platforms, the doors only opened on the other side of the train, confusing me and at least one other. At HarrowOTH, I boarded the train to Amersham, getting off at Chalfont and Latimer, then waited for the last train to Chesham, arriving there at 00:18. Perhaps foolishly, I got either a very tired or slightly drunk man to take a photo of me at Chesham, which used the final dregs of my phone's battery! As I exited through the ticket barriers, by dad drew up in the car, with hot chocolate, a duck wrap, water, and a new CD, which I listened to on the way home.
I very much enjoyed my day. Despite getting very little sleep- I did not suffer from any sort of tiredness all day. Despite doing it alone, not once did I feel bored or lonely. I did get exhausted- particularly the central london run around dash, at rush hour.
Everyone I spoke to or asked for help was very nice, loads of help with buses, platforms, even a little bit of chit chat. A guy on the Jubilee lent me a pen, etc. I never once felt desperate for the loo, 2 stops was enough. One at Finchley Central, the other, iirc, at Upminster. I had plenty of food, and I did run out of drink, but was resupplied in plenty of time. The longest waits were at Oakwood, for the bus, Woodford, for the loop, Finchley Central, for Mill Hill East, and Upminster, for c2c.
I was very pleased to reach Olympia so much earlier than I expected.
I was suprised at how many trains terminate before the end of the line. What a pain.
I've noticed quite a few stations don't have roundels. Particularly on the District. Richmond branch, Olympia, Barking and Upminster? Are there any more? or am I incorrect?
I'm pleased I made all the non-underground connections, and I am pleased that I know how to improve some of them, or at least know what i'm doing!
I'm pleased I finished at Chesham. It's where I was aiming to finish if I'd have completed it, and simply because the significance of the station on the network and for the tube challenge. (furthest out of London, longest gap between stations etc).
Despite being petrified of not doing so, I managed to keep my wallet, my phone, my paperwork and my ticket safely in my pockets all day! The only thing I lost was my pencil.
I dislike the stations that do not have an arrivals board, notably Harrow-on-the-hill. I dislike the trains that do not have sonia.
I still hate buses.
I nearly slipped over, once.
I can't run very far.
I hate writing long reports.
***** style stats:
Stations visited: 267/270 (Stations missed- Watford branch, Amersham)
Start time: 05:03
End time 01:18
Time taken: 20 hours, 15 minutes.
Number of people: Me!
Support team: Mum.
I may edit this if I think of other things to say.
Edits:
-On the day, I realised why the 'Bakerloo' line has its name... *facepalm*
-Its the first time I have ever been awake for more than 24 hours in a row.