You should just do what makes you happy. Obviously if you're over 40 (or indeed 12) then you're bound to get a few strange looks if people see you playing pokemon (although this mainly applies to the cards and anime... people are generally ok with the games, for some reason).
Happiness is what being human is about. Everything we do is based upon it, every move we make and everything we think is revolving around being happy in some way or another. So yeah, if you like pokemon, play it. But:
Pokemon hapiness - Social sadness = net emotion
If social sadness is a greater number than pokey hapiness, then your net emotion is negative, which isn't great.
In such a case you should probably give up, because you'll be happier in giving up pokemon rather than continueing to play/watch it. This principle is called the conservation of hapiness, something which I felt like... making up
But it makes sense when you think about it!