(Before you look at the images linked below, please try drawing a bike from memory and post a link in the comments.) A couple of days ago, Andrew Neher asked me to draw a bike from memory. He's asked a bunch of people to do this and has been posting the results at bikedrawings.tumblr.com. He said, "It doesn't have to be a good drawing or anything, actually, the ones I'm most interested in are the ones that are a bit off, where the memory of how a bike is put together isn't quite accurate, but of course, you can do it however you like."
I drew a bike from memory, and I asked my wife, my two daughters, and my daughter's friend to draw a bike, too. The results are fascinating and funny!