> I've also been poor, and one thing that sent me over the edge was a check that someone waited months to cash. Thought I had $200 in my account, and made a payment with debit card, only to go under $0.
While this isn't something that is directly taught (a checking account ought to come with detailed guidance), if you write checks, you should use your checkbook to track your actual effective balance separate from how much the bank thinks you have. If you write a check, no matter how long ago, you don't have that money anymore, so you can't spend it.
People often don't bother updating a check register each time they write a check, but if you have any serious threat of running out of funds in your account, you need to take the time to balance it to know how much you have.
(Also a great reason to never use personal checks at all.)
But the lack of any guidance in this regard, while supplying many ways to ask for your "current balance" (a complete fabrication once you've written any checks) is certainly one more way banks do nothing to prevent you from falling into a costly trap. I was lucky enough to receive very careful explanations of how a checking account really works when I was young.