I agree 100% texace. We often get the short end of the stick - anywhere from people assuming that because we are young our manners, presentation, etc. are all poor, to deciding that because we are young we have nothing worthwhile to say. I can't begin to count the number of times that I've been told (to paraphrase) that when I get old and cynical, I'll see and agree with some pessimistic right-winger's viewpoint. That's just an example, mind you - but that kind of condescension is very wearing after a while.
I now NEVER share my age online, unless specifically asked. Too many people decide that presenter qualifies the presentation, not the other way around.