First of all, because people have different experiences, different people will naturally have different ideas.

Second, if there are two people in the world, everything is the same to them, and their thoughts will still be different, because people's thoughts have changed too much, many of them are accidental, and many of them are just whim. If you miss this opportunity, you will never get another one. The ancient Greek philosopher famously said, "People can't step into the same river twice, that's what it means."