Every spring I have trouble trying to remember the number combination to my bike lock. Last year I was meeting a friend for a bike around Chicago and I had an hour to try and break the code because I had locked it to the radiator in the back staircase of my apartment building. I kind of know what the numbers are and I write them down every year. Then I try them all and they never work. I give it a few minutes just staring at the lock and then it just comes to me but I never EVER write it down I just figure that I will remember it for next spring but yet again I have forgotten it. But I am in luck because I have just locked the lock to the bike and it is still ride able!