[alex_reg]

I have the opposite experience.

Outdated comments are often way worse than no comments, because they can give you wrong ideas that aren't true anymore, and send you off in the wrong direction before you finally figure out the comment was wrong.

[elteto]

Indeed. I recently found this piece of code:

    if (X) assert(false); // we never do X, ever, anywhere.

Then I look over to the other pane, where I have a different, but related file open:

    if (exact same X) { do_useful_stuff(); }

It got a chuckle out of me.

[jgilias]

Did you update the comment? :-)

[withinboredom]

// there are two kinds of mutually exclusive commentors

enum kinds { writers; readers; updaters; }