Just as buying things on a credit card is using borrowed money, procrastination is really borrowed time. For both, the fun ends when you have to pay up.
The quote "Procrastination is like a credit card: it's a lot of fun until you get the bill" is attributed to young actor Christopher Parker. If you're not procrastinating productively, putting off necessary tasks will just increase the agony of making up for that time later — just like using credit without budgeting can come as a shock at bill time.
Next time, when you're tempted to procrastinate, consider what that borrowed time will really cost you when it comes down to crunch time.