Put your pride aside and comment your code for good

Not sure about that. The reason I personally only write comments occasionally is that the code changes and the more comments there are, the less likely they'll be maintained along with the code.

If I'm going to make a comment, it better be worthwhile. A heuristic I find useful is "why, not what". That is, if the code has an unusual but justified feature, place that justification in a comment.

Sounds like the author is waist-deep in a crusty old codebase, but I'm not sure comments on every line are necessarily the solution.