Faking Caring

I was chatting with a guy, he is one of those nice guys that talks to everyone and expressed interest in everything.  I met this guy before, I know what he is exactly like.  He really isn't interested in anything, except making small chat, as that's what they taught as being nice.  But I keep forgetting to switch off my listening, as he meant nothing he says and everything was just hot air.  Why can't he just let the silence be undisturbed?