It's never too late to comment :)

The other day I was re-reading a fic I'd read about five years ago, and I spotted a typo in my comment from back then and fixed it.
The next day, the author responded! I guess they'd been busy when I first left it, and were around to see the email about the edit.

And then yesterday I commented on a fic from 2012. Guess what happened, the author responded and was overjoyed to learn that someone had found one of their older works.