I, too, am wondering if you changed your name legally to your current name.
I think that a name change usually draws people's curiosity except under certain circumstances, like marriage. If a person's name is really weird or if it sounds foreign to American ears, a change will seem natural, but people will still ask questions. If you change a more common name, that will probably get you a lot more attention, but I guess it depends. Is there any crossover at all between the current name and the new one?
You could tell a great story about calling yourself this name in childhood, for people who wonder about the change and don't know about your past. Could get tricky, though, if you want to avoid talking about your real birth name.
As for the people who don't take you seriously now, this will give them something new to talk about, but CAN they take you less seriously? Who are they? How badly do they treat you in the first place? Are you on the way to smoothing things over with them? Do you care what they think?