As an accountant, it's no surprise that I think about numbers, a lot. Even in my personal life, I'm a unit-price-calculating, Excel-formula-using machine. There's a picture floating around of four-year-old me sitting at the kitchen table with a calculator and a bank statement (doing my first bank reconciliation, I'm sure), and at roughly the same age I proudly declared while at the bank that interest is "when your money makes money".