Usually no, unless I’ve left a reply disagreeing then someone else comes along and downvotes them, makes me look like an ass who downvotes anyone I disagree with. I also check my own comments to see if people agree with me but I’ll keep the comment up either way, if I do change my mind I’d rather leave a new comment or add stuff in an edit.

It’s not too difficult to bot votes on lemmy so they’re even more pointless than they are on reddit.