 And that means a quarter of your skeleton is made of foot bones. Wait, that's crazy. Right? Tons and tons and tons of foot bones. Okay. So why is that? Well, we descend from apes. We are primates, and primates live in trees. And you need in trees to have a mobile foot. So think about an orangutan's foot or a chimpanzee's foot. They can use their foot in the same way that I use my hand. They can grab onto things.