I was in a pub recently and there was a bloke in my line of vision who was persistently jiggling one leg up and down. Even though he was on the other side of the pub, he was ruining my lunch. (Was very tempted to go over and bash him).
Why do some blokes (it's usually young laddish blokes for some obscure reason) do this? You know, where they kind of balance their leg on one toe and jiggle furiously...