Thinkers have always wondered where it comes from. We can conceive of light because of darkness, and of death because of life. These things have their opposites, that give them meaning. But Meaning itself seems to have no opposite that we can conceive of. Even when we say something is 'meaningless', we are giving it some meaning.
Meaning just seems to be different.
Our understanding of Meaning, it seems, must be different from our understanding of other things. We can grasp it intuitively, but not, it seems, theoretically. But that has not stopped us trying, down through 2,500 years. Indeed, the ordinary person does grasp the importance of Meaning, intuitively. More to write here.