Hmm... you're wanting to take your vote back?
Well, that's a bit tricky. See, we do a lot of stuff with your vote, using it to work out the popularity of what you voted for, compare that to all the other things voted on, tally up our leaderboard, work out your reputation. Someday we'll do a little cartoon showing just how hard your vote is working.
Anyway, taking votes back messes all that up, so we give you five minutes, in case you just mis-clicked. After that we've got to say no take-backs. Luckily, votes are free, so feel free to throw them around left and right wherever you see fit.