Sometime around 300,000 years ago, give or take, the brain you are using to read this sentence finished its last major hardware update. What you have in your skull right now — the roughly three-pound organ responsible for your quarterly targets, your Slack hygiene, your inability to stop checking your phone during meetings, your best ideas, your worst decisions, and your persistent sense that something is slightly wrong — is the same basic architecture that helped your ancestors track prey across open savanna, navigate complex social hierarchies around a fire, and survive in environments that were actively trying to kill them.