[onychomys]

Code shows how something happens (i.e., a string comes into a function and is parsed and only the date from it is returned), but it's so bad at showing WHY something needs to happen. My comments are almost always about why I'm doing it in the way I am, complete with examples of test cases where the users broke things in ways I wasn't originally expecting. Ten years from now, the code part will be rewritten using whatever crazy new stuff the language supports, but the underlying need for doing it at all will probably still be around.