You Can Never Prove Others Think

You can never technically prove anyone else has a mind. Since you only ever witness someone's outward behavior, their internal experience remains a total mystery that you simply choose to trust.

This philosophical puzzle highlights the strange reality that your own consciousness is the only one you truly experience. Even though we feel certain that others are thinking, it is an inference rather than a proven fact. Thankfully, our brains come pre-wired with a theory of mind that lets us easily navigate social life. We instinctively project our own internal states onto others, making the world feel shared even if we cannot peek behind the curtain of another person's thoughts.