Had a 3 key combo (0-9;0-9;0-9) when I was 12 with an attached chain... I was playing baseball and after the game the lock was open and the bike was gone.
More humorously, in college I lent my keys to my roommate who promptly lost them... I couldn't ride for 2 days. I ended up renting some bolt cutters and having to prove to the campus police that it was indeed my bike. They then told me they would have cut the lock for me at no cost. I got my keys back 2 weeks later ...