Just because someone asks a question doesn't mean you have to answer. My favorite technique in dealing with busy bodies is to turn the tables on them.
I do something similar. I apparently am not interesting enough for people to ask me personal questions--hasn't happened so far.
But I get bored talking about myself and would rather listen. So when people do ask the basics (What do you do for a living, etc.), I give them an answer that will bore them to tears ("I'm an editor in a think tank--it's sort of like being an English teacher, only for grownups"). Then, as their eyes start to glaze over as they are remembering their worst teacher ever, I say, "But that's enough about me--I'm sure your travel adventures are much more interesting--tell me about your train trips" (or something similar). Works like a charm--I hear many interesting stories and nobody ever goes back to asking me about me again!