I get this, but I don't really remember seeing this happen to even small people in the gym. And I was 160 once, too. Not that I spend my time watching others, but I am usually aware of waht is going on around me, to a point.
I feel fairly knowledgeable and have made decent strength gains, but even when I see someone doing something "I" think is ridiculous(or dangerous), I don't approach them. Maybe that's just my personality type, who knows.
I have been approached with questions before when I do something out of the norm -- people always ask me about board presses. And I always answer. I refuse to be an asshole just because someone's curious. In fact it usually ends up with them walking away, because I start to ramble on.