My sister's son Robby, I'm not afraid to say, is a genius. His obsession with letters started around 18 months or so (maybe sooner). He knew all of the alphabet, along with their sounds, and even started to spell words, gaining quite the vocabulary at age two.
At age three (now), he happily replies, "I want to learn!" when asked by his mother what he wants to do on any given day.

His obsession recently has been states. Once he learned them all, he moved on to state capitols (he can name them all... which I can't even come close to doing). Next, he was on to countries. He started with South America, learning all of the countries within the continent, and their capitol cities. His room is covered with maps of the world, and his punishment when he does something wrong is to take them down, which will make him cry more than anything else.
Unfortunately, I don't see him much. Holly's family lives in Florida, where the plane tickets don't come cheap. I am grateful for modern technology - computers, blogs, web cams, email, and the telephone. Holly fills me in with the details when she can, and there have been a couple of recent "Robby-isms" that have stuck with me. This kid is a crack up.

He has overheard his parents say that he is a genius, but I'm not sure he fully knew what a genius was. However, the following statement made by him suggests otherwise.
Holly (paraphrasing): "Robby, it's time for you to take a nap."
Robby: "I don't need a nap! I am a genius!"
He also has an impeccable memory, and loves music. Holly has recently shown him the Fresh Prince of Bel-Air rap, which he will watch over and over again. After learning part of it, I give you another reason why this kid is just too much... and much too cute.
Holly (on the phone, away from home, talking to Robby): "Hey buddy, how are you?"
Robby: "Good. I miss you, mom."
Holly: "What are you doing?"
Robby: "Just chillin' out, maxin', relaxin', all cool."
Not only is he a genius, he apparently has the wit to match. I'm thinking he probably got that from me. (I really just wish I was that cool.)