So this is Thanos. Single dad. Two adopted daughters. Genocide plan. Loves both equally. Normal guy. Now Thanos has a problem. His home planet was running out of food, so he suggested killing half the population to fix it. They said no. The planet died. And instead of taking literally any other lesson from this, Thanos decided the lesson was that he was right and everyone else was an idiot. So he's been thinking about this for decades. Just a man, alone with his thoughts, absolutely convinced he needs to kill half of everything. Not feed everyone or create new resources. Kill half. That's all the plan there is. And to do this he needs rocks.