The ß doesn't make any sense here. The sentence "Pessimist: Jemand, der darüber, dass kein Haar in der Suppe ist, solange den Kopf schüttelt, bis eins reinfällt" is pretty funny. The word "darüber" doesn't mean "above" here but "because of", btw. It's simply "Pessimist: Someone who finding not a single hair in his bowl of soup will shake his head until finally one will fall into it (and so, finally giving the pessimist the desired feeling ;-)
It doesn't have anything to do with "someone eating his soup with a hair in it"