This was my first marathon and I had no idea what to expect. It was amazing.
At the start I got caught in the loo queue so was in a cubicle when the klaxon went. I didn't see the numbered pens as I rushed to the start so ended up running in pen 6 instead of pen 8.
For the first few miles I concentrated on keeping slow, watching the crowd and greasing my nipples. The best costumes included a squad of Roman soldiers and some beer bottles - I would have hated to run in those outfits. I started to feel fatigue in the front of my thighs at Mile 10 but ran past the couple who got married on Friday and were in their wedding outfits: respect.
Going through the tall buildings of Canary Wharf, the back of my right thigh cramped up and I had eaten all my supplies. There were no gels left at the next station and there was a big gap between the Canary Wharf Lucozade station and the next - this was the only stretch where I wasn't smiling. I refuelled on Embankment and pushed on through, stopping briefly to stretch out my legs. The crowd helped so much. The back of my left thigh went near the TV camera in front of Buckingham Palace (I hope the BBC didn't get that moment), and I pushed on to finish before the big clock hit 4:00. My final time was 3:56.08.
Stunned that I could still walk at finish, I met up with my wife Sims who was only a couple of minutes slower than me. She should have beaten me as she had done much more training but she got stuck behind the slower runners in Pen 9.
The Worst Bits Cramps at Canary Wharf and Buckingham Palace.
The Best Bits The crowds shouting my name; kids handing out Jelly Babies (mmmm); seeing my 13-month-old son at Mile 13; hugging my wife at the finish; massage at the charity reception (Macmillan - awesome); champagne when we finally got home.
What I would do differently next time? More and smarter training. I missed most of the speedwork and fartlek training, concentrating more on long slow runs and cycling.
But I loved it. I'd definitely do it again, although the Bordeaux Marathon sounds enticing!