The Briton, who will make his marathon debut in London next year, was roared on by the crowds who had lined the roads before he dropped out of the race at the halfway point as planned shortly after the leading pack had crossed Tower Bridge on Sunday.
The Olympic 10,000 and 5,000 metres champion, whose sole objective on Sunday was to pick up tips and pointers for running the course next year, hoped that practice will make perfect as he admitted not everything had gone as intended.
"I woke up late (and I thought) I'm going to miss the bus," Farah told the BBC.
"The biggest challenge (during the race) is picking up the drinks and making sure you pick up the right drink. I made a mess of it. At one point I had to stop and go back for it. Things like that don't help as you want to save energy.
"I've learnt the biggest lesson of my life. If I had come here next year and made a mess of it, mentally I don't think I could have dealt with that. It was good practice for me. It opened my eyes for me," added the 30-year-old who had been criticised in the media for his truncated appearance.
Farah kept up with the leading pack, which ran the first half of the race at world record pace, as they ran round the streets of London in front of large crowds under bright sunshine.
"It was incredible. Everyone was cheering just the whole way. It was unbelievable. The atmosphere is incredible," he said.
Ethiopia's Tsegaye Kebede won the race.