By design we can not not be unique. From that basis onwards, one can accentuate or smooth those differences. Since being unique is the norm, we rather call "unique" people whose accentuation is a statistical outlier, which must be innate for if it's not original it will not be uniqueness but pretension. Such outliers might be dormant, waiting for a stimulus to bring them up to light. So there's a lot of people who is unique but whose dormant outlier remains unsuspected. Thus, experiences might not create uniqueness but sure they are vital to find it.