Yes!
I did fall off once, in London, due to the sheer number of cyclists packed up against traffic lights. I couldn't start properly when the lights changed and collapsed in a heap. No harm done. It was difficult for the first 10 miles because it was so crowded that you had to concentrate really hard to avoid crashing. After that I loved every second and cycled with a big stupid grin on my face. I was really surprised and thrilled to discover that I passed loads and loads of people, particularly on the hills. I had just sort of assumed I would be miles slower than everyone else.
I got up all the hills ok except Ditchling. It was quite hard just pushing the bike up there. Saw some awful crashes but avoided the ambulance myself.
Arrived in Brighton after about six and a half hours, in bright sunshine, crossing the line with Batman, Spider-Man and Superman. Nothing ached except my smile muscles.