Examples like the one shown below can occur because of the repayment structure of the typical credit card account. When you make a payment, it is made up of principal and interest. The principal is the amount of money you actually borrowed; the amount of interest is calculated off of that.

Insert Credit Card Payment Example from page 11 of the Young Adult guide.

As you will notice in the example, when a consumer makes a minimum payment of 2% on a balance of $2,000, approximately 71% of the payment is applied toward the interest on the borrowed money. Only 29% of the payment is actually applied to the principal, or borrowed amount. That's why it would take so many years to pay off the account - most of every month's payment is going to paying the interest on the loan. By roughly doubling the amount of the minimum payment, the same loan would take about 5 years to repay, still worth avoiding if you could afford to pay more than the minimum.