What if I have no idea if or how many times I claimed the Hope or American Opportunity Education Credits? It was a decade ago - what should I do?

The credit is only available if you have not taken it 4 times already.

If you are not sure that the credit was not claimed four times already, you won't be able to answer that question and you won't be eligible for the credit. 

You could check the returns from the years you attended school. (parent's too if you were a dependent) The limit is 4 times per student, so if your parents claimed it on your expenses, it counts as a time you took it. 

The IRS has tax transcripts on file, but they would not be able to tell you how many times it was claimed. 

They will, however, contact you if you take the credit more than four times, charge tax, interest, a penalty and possibly ban you from that credit in the future (for example if you have a dependent student)