Looking down on people is human nature. I'm self taught myself, no formal education of any kind and I'm the first person in my family to work a white collar job like this. My experience is even people in my own family can't help but make snide comments when I succeed. Some time ago I walked out of ear shot at a family gathering and my own grandmother dismissively mentioned that my success was simply because "he applies to a lot of jobs", she loves me and means well but even she can't resist. Let it roll off you like water on a duck.