Younger ones have a hard time coping with the fact that you won't eat them. Lol. As it's been said in another comment give it time. I got monty as an adult, and she was a rescue with zero handling her whole life, so I got a few love taps, but my patience helped. What I would do is once a day, when she was out, I'd put my hand on the outside of the tank. She wouldn't strike, so I put my hand inside the tank, she'd strike but miss, or wouldn't strike at all. Patience is a virtue when working with snakes. He'll learn eventually.