I also was interested in the apearence of sharks and especially of great white ones in the med, since as a kid i always believed it was a shark free zone

. Mainly white sharks of the med behave differently because of the poor amount of food in benthic zones for these predators.
Thus they appear to have a pelagic behavior and therefore are rarely seen near the coast. The poor food supply also makes them prone to test and eat whatever seems chewable, this could also be interpreted in a more agressive behavior then white sharks shows in other regions of the world.
But as spaghetti mentioned, don't get afraid. The chances of getting hit by lightning are probably much higher than beeing attacked by a shark in mediteran waters
Christophe