At 18 you have some maturing to do but you are not a kid.

You can buy a rifle or shotgun, go to prison, join the military, and own a venomous snake.

I have a friend that is in his 30's and was given a rattlesnake and now has a few different hots. He has no business owning them but he does. It sounds like this 18 year old had more experience than my friend. I don't see the issue with his age.