But the biggest event that very few people talk about, the ones that affect us the most, is the Neanderthals at the Last Champ event. The Last Champ event happened 42,000 years ago. And what's interesting about the Neanderthals, they had 125 grams more brain tissue than my patients do today. So they shrunk their brain down. And what did this allow them to do? It allowed them to become more isotopically light. So we are humans that show up on the planet. And what did we notice about their name? Neanderthals. Why are they called Neanderthals? Because above the 51st latitude, where is the only place that their bones have been found? When they went higher than that, it turned out that they couldn't live at that level. We show up and we can go all the way up to six. Yeah, why could Cro Magnon do it? But Neanderthal couldn't. Well, we don't know that answer, but we do know why Neander couldn't do it because his brain was too expensive to live high up on the planet.