Cosign

The bane of every responsible parent...who has an irresponsible child.

When a parent co-signs for a loan, that parent is equally on the hook to pay back that loan as the child who signed for it in the first place. Take the student loan crisis. Vast numbers of parents co-signed student loans; most pundits predict a majority of those loans will go unpaid (i.e. lots of sociology majors will go bankrupt), and the parents will then go bankrupt by dint of having signed those pieces of paper, or rather co-signing the promise to repay the bank the money.

Fair? Not fair?

Well, what if it was you who loaned that sociology major the $83,500 to go to college, believing...even betting a big part of your retirement money...that you'd be paid back that money. And then it turns out that the kid flaked, and now his parents are on the hook for that loan. Are you ok just saying, "It's okaaayyyyy. That $83k plus years of interest? It's all yours. I give it to you. The world really needed that n-plus-1th sociology major. Thank you, and yes, please leave room for cream in my blonde roast."