Just wondering whether anyone has ever experienced the sheer agony I am in at the moment.

Okay, I had a treble free period today so decided to come home early, as it is a really nice sunny and warm day today me and my mum decided to go for a bike ride.
Towards the end of the bike ride I was cycling up a hill and my bum was off the seat. Then all of a sudden my gear slipped and I smashed my knee on that stubby thing thats in the centre of the handle-bar where the two ends meet.
I was in agony for the rest of the bike ride and still am now, has anyone ever done this? You really know about it when you do.