Do we really understand how credit card interest works? I know I didn’t and really didn’t want to know until recently.  I was shopping at a popular department store and I let the cashier sell me a credit card.  After a few months or so I noticed my balance wasn’t what I thought it should be. So I started to check into how this interest and payment thing really works and I found some information everyone should read that I must share with you. How does credit card interest really work?