I've seen a quote from somewhere that goes like this. "If you never heard from your debtors again, then it is worth it." I know it is poignant to lose that amount of money and over a friendship that was probably built from years of spending time together to boot. But in retrospect, one can only accept the truth and move on. Or if you're really bitter about the whole ordeal you can always sue him, you found a way to at least see that he's living a pretty affluent life, you could find out where he is and send him a subpoena. Blue pill or Red pill bro, you choose.