2. You Do Not Actually Know Your Interest Rate
A surprising number of people can tell you, without hesitation, their credit limit, their rewards structure, or their annual fee, but cannot tell you their actual interest rate with any confidence. This particular gap in awareness is itself a meaningful sign of misuse, even before considering anything else about how the card is actually used.
Consider why this gap tends to exist. A card used exactly as intended, meaning the full statement balance is paid off every single month without exception, makes the interest rate almost entirely irrelevant, because interest is never actually charged. In that scenario, it is genuinely reasonable, and not a sign of any problem, to not have the interest rate memorized, in the same way you might not know the exact terms of an insurance policy you have never needed to claim on.
The moment you find yourself unsure of your interest rate specifically because you are uncomfortable checking, or because some part of you suspects the number might be higher than you would like, that discomfort is worth paying close attention to. It usually indicates that a balance has been carried for long enough, and interest has been paid often enough, that the number should matter to your monthly finances, and yet it has not been looked at.
Pull up your most recent statement, or log into your account directly, and locate the section showing your current annual percentage rate. Many cards, particularly ones offering rewards or cashback, carry interest rates that are considerably higher than a standard, no frills card, precisely because rewards programs are often funded, in part, by the interest paid by customers who do carry a balance. If the number you find is higher than expected, treat that discovery not as a source of shame but as genuinely useful information, since it is the first real step toward calculating exactly how much any ongoing balance is actually costing you each month.