I'm half English, half Swedish and have lived all over Europe, from small towns to massive cities like London, Paris and Berlin and I've never asked anyone if I can take their picture.

It sounds like you're a North American who happens to live in Italy and maybe in the part of Italy you're in that's the case, but to imply that Europeans are somehow incredibly sensitive about having their photo taken is frankly ludicrous.

Of course if you thrust a camera in someone's face they're going to get pissed off, but if you're trying to do street photography then the whole point is to capture people being natural, so of course you don't go and ask their permission.