Student loans, mortgages, cars, weddings. All seem to be great excuses to spend more than you can afford. I was smart on 3 of the 4, but reluctantly admit having a $30k wedding. Before we planned it, our parents each offered to contribute $10k. We had the money for the rest and chose to spend it that way. It covered a lot - rings, dress, venue, reception, honeymoon. I can't say I regret it, it was a choice we made, but I also can't pretend I really understood the impact of spending so much money. I'm sure I would've done things differently had I been exposed to MMM back then.
The saddest part to me is my parents unknowingly lived the MMM lifestyle (first by necessity, then by habit) and they taught me the importance of saving. On top of that, I have a finance degree. Even with that background I still didn't fully understand money until my 30's. Luckily for me enough of my parents' habits rubbed off and I'm in decent shape, despite my ignorance. But if I didn't understand the value of money until recently, I can certainly see how others can be oblivious. If people don't spend their early years struggling for money, it's no surprise they take it for granted.
I saw someone post a suggestion for the OP to give the gift of personal finance books. I second that. If it's uncomfortable for you to give the books, then buy your normal gift and leave the books anonymously on the gift table. He may never read them, but you have the chance to legitimately change the course of this guy's life if he does.