I constantly see people making the claim that "comments tend to become outdated." The thing is, I think I have seen maybe two or three outdated comments my entire career. Outdated information in separate documents happens all the time, but in my experience outdated comments in the code itself are exceedingly rare.

Have I just been lucky in who I work with? Are certain industries more prone to this problem than others? Do you have specific examples of recent outdated comments you've seen? Or are outdated comments more of a theoretical problem than an actual one?