Having children is weird. One minute your wife says "I'm going to have a baby" and then five years later its playing chess, and its trying to suck you into an exchange of queens. Marcus actually checkmated me yesterday, and is still crowing about it. (Its true I had been coddling him along a bit, but it was awful shock when it happened). At one stage I noted he had not moved either of his knights yet. He said (direct quote) "I have not found them to be very useful".
Besides playing chess and talking like a PhD student he can also reach stuff on the mantelpiece now.