Mental age might be a little difficult to determine - for example, I believe that wisdom is an important goal, but maturity is a price too high to pay, so I strive to gain experience and the ability to think rationally without abandoning fantasy and dreams. That is why I am proud to be a nerd, I do not abandon fun just because it is considered childish. I watch Power Rangers and play Pokémon, I have all Digimon themes on my MP3 player, always carry a DS with me and actively use the Pokewalker, I fantasize. Yet I consider economic implications of my purchases, wonder when the time will be right to find my own place to live and worry about political changes. I am of a very undefined mental age.