If you want, the next time you need a gift get him a physical Bitcoin and tell him to keep it safe. If 5, 10, 30 years from now he realizes that gift you got him is worth a fortune well that might get him into it. If Bitcoin fails well it didn't really cost him anything except not getting a different gift in the past.
I don't know much about the physical bitcoins but just did a search. Are the Casascius ones what you're talking about? That was the first thing that came up.