I'm actually really open about it. EVERYONE I know or just even barely know, knows im obsessed. I never have to hide it in secret unless i'm playing in class(which ive only done ONCE last year). But when I was little I was teased for being so "tomboyish" that no one talked to me except a few guys. Girls hated me, but the guys liked to talk about Pokemon and Yu-gi-oh with me, LOL. So i did hide the fact that i played pokemon a lot when i was little. Now, everyone knows and I actually seem to have a lot of friends because i'm so open now. I guess it kinda depends on yur situation whether yu choose to be open about it or not.
It's kinda weird actually. With my really close friends, I can talk about my love for Pokemon(even though they dont play so theyre thinking "wtf" the whole time), but with my VERY best friend, I never talk about it, or its embarrassing if I read the walkthrough in front of her. I mean, I play Pokemon and read Pokemon in front of her, but I'm not really comfortable with it.