During a much-needed break from work, I struck up a conversation with a colleague. It started out as your typical workplace conversation, but I could sense that something was weighing on her mind. So, I asked her what was going on. It turns out that while she was reviewing her bills, she spotted a rather distressing fact about her credit card. Like so many of us, she assumed that whenever you use your credit card to make a purchase, interest doesn’t kick in until 30 days later. Nope. The credit card determines when the interest starts. So, for her and using a Chase credit card, it was 21 days….