My son. It's tanks. He's 12 and can go on for hours about them, rattling off their armor thickness (in mm), caliber of their guns, horsepower of their engines, declination and traverse speeds of their turrets, etc. I took him to a tank museum one time, and no shit a quarter mile from the museum he sees the tank out front and he goes: "That's a Sherman M4A4!!" Ten minutes later we're parked and walking up to the museum, I look at the tiny info placard, M4A4, think to myself: "What the fuck."