I’m fascinated by the existence of so many foods. Who decided to boil tree sap for 3 weeks to make maple syrup? Who agitated cows milk vigorously for 20 minutes to discover butter? Who saw cheese for the first time and decided to still eat moldy milk?

I thank those nameless humans for their service to society.

Butter was discovered by accident when humans were still nomadic tribes. Milk was transported in animal skin bags and the agitation from travel turned it into butter. Probably being chased by something or running very fast.
They clearly had good cardio if they were agitating it that vigorously for long enough to make butter! Forget fitness watches, maybe I should wear a sack of milk at the gym to see if I’m working hard enough.
Runners Are Discovering They Can Churn Butter on Their Runs—and It’s Surprisingly Easy

Some runners on social media are successfully churning butter during their runs.

Runner's World