Why do people do it? There's always people running near where I live. Not for any reason - not trying to catch a bus or a mugger that's run off with their wallet. Just running along the street, sweating - and usually listening to an i-pod - because clearly they find running boring.
There is no need for it. We can keep fit by playing competitive games. We used to run and there used to be a point to it but surely we have evolved beyond that now that we are civilised modern people!?!
Running was invented for one of two reasons:
1. Something that wanted to eat you was chasing you
2. You were chasing something you wanted to eat
Having seen no sabre-tooth tigers or gazelles in my local high street I figured anyone who does run around the town is probably mental.