It took a lot of trial and error to figure out that food and water were the two essential things for survival.
Back in the caveman days, you didn't see a whole lot of thriving metropolises. The reason is because people hadn't yet figured out the keys to life. They tried a lot of combinations. Running and cobras. Clouds and deciduous trees. Enlightenment and crying. But no matter what they tried, they'd end up dead. The answer eluded them for many years.
They did get close a couple of times early on when they tried food and singing one day, and then water and fainting the next. But it wasn't until many years later that one particular caveman, having ingested some very spicy peppers, sought relief from the waters of a nearby stream and thus discovered the winning combination of food and water.
How they would laugh to know that today, food and water are readily available via bundles sold on websites just like this! Either that or they'd throw spears at us. You know the old saying, you can lead a caveman to water, but you can't make him not spear you through the heart.