:) I'm 16 years old too.
the only thing that makes me play minecraft is the creativity and building, its increase your imagination and creativity, so its useful for me no one can say to me you are old for this game, and i don't know i see these killing zombies and crafting and searching is fun but there is no benefit i think you are old of these, but you can play the game whenever you want, but you are In important age you have to develop your skills and think about your future, and do whatever is fun for you but it would be better if it has a benefit.
Sorry for my bad English.
Hassan.