I don&#x27;t like downvotes because people mostly downvote what they disagree, not spam and whatnot.  Having some ideas and habits contrary to what&#x27;s popular, I experience this first-hand here on HN.  And probably this is a reflex, most often when one sees someone disagree him, he feels a spontaneous whim and thinks that his argument is not reasonable.  And only after a bunch of seconds does he understand that the other one actually poses a sound argument, criticism, etc.  The HN&#x27;s upvote-downvote sytem lacks undo, so unfortunately when you regret a downvote, there&#x27;s nothing to do.