If you don't you're probably losing money. Not a month goes by that I don't find a mistake. Somebody charges me for a service I didn't get. I ordered something but never received it. Last month, my husband asked me what I bought on Ebay for $485. and paid for through Paypal. I didn't. Someone opened an Ebay account through my Bank America and paid for it with my new Paypal Account that I never opened.
Charge cards are the same way. I rarely use them. So it helps, but the little charges appear, and they are often charges that the bank put on that you were unaware of. For example, I was charged for disabilty insurance. I had receive 90 days free, and then the bank started charging me for it. But I never signed up for it.
I could go on, but suffice it to say, check your statements. Sometimes, I do so with dread, but don't let fright keep you from your money. It will pay you back many times. In fact, my bank compliments me on my diligence.