I\’m a little scared about my friend?

Okay I have a friend whos name is Luis Carrillo. He plays alot of Call of Duty Modern Warfare 2 and he’s obsessed with knives. He looks up videos on how to throw tactical knives at a certain distance and other things. Lately he’s been playing with real knives in real life and trying to throw them as far as he can. He is hoping he’ll hit someone from far away even though I dont think its possible for him. He’s hit a couple trees but thats it. Is this normal for a 16 year old kid? I’m afraid he’s confusing the real world for the virtual world.