I do it for the exact same reason. I was asked to work on a project one time (small OS) and I was going to remake the core. The person had made it a couple mont

I do it for the exact same reason. I was asked to work on a project one time (small OS) and I was going to remake the core. The person had made it a couple months ago and had no idea what was what when I asked him about it. If he had just taken the time to write a comment here or there explaining some of the things, it would have been much easier than debugging the entire OS (which I had to do). The worst part was that he put in all of these extra "checks" and "lists" containing information each time programs would run (ect.) and they turned out to be completely useless and affected nothing. Anyways. My point is that a comment here or there on projects would help immensely. Especially if you may drop a certain part of a project and not maintain it for a period of more than a few days. Not all code is self explanatory.