Last year I was fishing on Clapham pond, I was float fishing in the side for small carp, catching a few and generally enjoying the sunshine. I'd been there a couple of hours so I'd had the usual, kids asking for floats, winos asking for money and the odd 'expert' giving me advise, when up walked a big scruffy guy with a can of special brew.
He told me "you should put a weight on and fish against the island, that's where the big 'uns are". I thanked him for his advice and carried on fishing. A couple of minutes later I glanced round and he was still there... "WELL, PUT A WEIGHT ON THEN... I haven't got all day!"