Why is this boy so annoying?

So there's this boy in my cl who behaves like a complete jack, yet mostly to females. Not only that, he can't take no for an answer and is as stubborn as a mule. Today in cl, he kept intruding on my personal space and touching my things even when I told him not to...three times! It's like he tries everything in his power to annoy people and feeds off of attention. Even if you ignore him, he tries twice as hard. It took every ounce of my being not to respond negatively. I hardly converse with this boy, I'm the quietest one in the class, so why am I suddenly a target? By the way, I'm 18 and I believe he's in his late teens as well.