I honestly really like the idea of letting your kids grow up with nicknames, and then choosing their own name once they are a certain age. But there's so many things wrong with that innocent of an idea. Birth certificates, your kid really liking Cait Sith from FFVII (I just saw your sig, I love Cait Sith, only using as an example).

I've just always thought its so weird that someone else chooses your name for you. Like, I imagine my son being like "why did you name me Joe? I'm Michael as FACK."