Today, the future is about as predictable as it's ever been. If the government guarantees to pay you $200 when you turn 65, there are laws in place that say they have to do it. But our brains don't know that. So when a guy in a white lab coat walks up and offers to pay us $100 in a year, or $50 right now, our brains still tell us to go for the rat stew.
This is what's called hyperbolic discounting, a scientific term that means your brain is about as far from rational as it can get before they're legally required to keep you in a zoo enclosure. We're only half kidding. Hyperbolic discounting puts us on the level of pigeons and rats in the realms of fiscal responsibility.
It's not just a lab experiment. There are entire industries that rely on your inability to think rationally about the future. Our whole economic crisis was kicked off by borrowers taking on loans they couldn't afford, after lenders offered them lower payments (or no payments at all) for the first year. Credit card companies still rely on your brain to make purchases now that you won't be able to pay for at the end of the month. Top Gun drill sergeants rely on your ego to write checks that your body can't cash.