if you’re like “this fic was posted [x] number of days/weeks/months/years ago, it’s too late to post a comment,” let me tell you. no. it is never too late to comment. maybe someone else will see your comment and decide to read it. maybe the writer will see it, maybe they won’t, but if they do i guarantee they won’t be like “who’s this n00b commenting on my old fic” they’ll be like !!!! someone is reading my old stuff!!!! every time an AO3 comment is posted an angel gets its wings etc etc