The dumbest thing you've ever dun?

The dumbest thing I've ever "dun" was reply to this thread. And form that last sentence. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And that last one. And falling off my chair.