I've never been able to lend the kind of money you two guys are talking about. I have, however, been asked to co-sign a few car loans over the decades all of which I've refused.
I do admit that when possible, I give money, I never lend it nor were I to be a person of means, change my ways. This way, if it does come back (as has occurred on several occasions) then fine, if it doesn't, it's no skin off my nose; meaning I tell the person if they can pay it back then fine, if they can't then that's fine as well.
Ol' Ben Franklin said it best, "Never a borrower or a lender be." or words to that effect.