25yo living in Paris, France... and nobody cares when I play with my DSL in the subway.
Actually, nobody cares about other people/freaks/whatever in the french subway... and I think it's pretty normal for people to see an adult playing on a handheld console due to the democratization of video games since the early 80's.
It could have been weird seeing an adult playing gameboy 20 years ago in a public place, but it isn't anymore because the first generation touched by this democratization is now adult and this people have kids, work... do stuff in "REAL" life.
So in my opinion, most people are now aware of this geek attitude even if they don't even know the word... and if some people stare at you just like if you were a freak or some kind of retarded, ignore them.
I guess they don't know what a passion is, and I wouldn't exchange my life with their lame one cause I cherish the bound guarding my "child" side against the fact that every day I become more and more an adult.
Hope you understand what I wanted to say !