Common sense is the collection of prejudices acquired by age eighteen. — Albert Einstein

Common sense is the collection of prejudices acquired by age eighteen.

Author: Albert Einstein

Insight: We like to think of common sense as obvious truth—the stuff everyone just knows. But Einstein was onto something darker: most of what feels self-evident to us is actually just inherited assumptions we picked up so early, we forgot we learned them at all. Your gut reaction to what's "normal" in relationships, money, ambition, or how people should behave? That's not universal wisdom. That's your particular culture, family, and generation speaking through you. The tricky part is that this doesn't mean common sense is worthless. It's actually useful—shared prejudices let society function. The problem emerges when we mistake familiarity for truth. We reject ideas that feel weird not because they're actually wrong, but because they clash with the defaults we absorbed by eighteen. History is full of "obvious" beliefs that were just common sense to their time: that women couldn't do math, that stomach ulcers came from stress, that you shouldn't question authority. They felt rock solid until they didn't. The real skill isn't abandoning common sense entirely. It's learning to notice when you're following it, and asking yourself whether you're following it because it works or just because it's comfortable. That small pause—that's where actual thinking starts.

Source: Out of My Later Years, p. 160, 1950