Hahaha...with EVERYTHING that happens in the DCU, all the sci-fi/mystical chaos, people wearing costumes with cool names having adventures, the dude being 10 bothers you? Ridiculous. For me, once you accept that a grown man would become Batman or that there are aliens out there that look identical to humans, you accept it all. Also, reading the golden age Batman stories, it seems like Dick is no older than 10 as well.
Damien is great, when penned by Morrison. I loved him and Jokers scenes together towards the end of the Return of Bruce Wayne/Black Glove arc. And its a shame that he and Dick were split up, I loved that duo.