My uniqueness is mine, so why question it?

We're all unique and yet there exist a plethora of frameworks and tools which seek to identify our personalities. Surely this profiling is doomed to fail at the first hurdle, indeed how can I be categorised if I am me and no one else? I accept that certain personality traits can be more or less prevalent in each individual, and I'll be the first to admit that to date, my personality "type" has always been spot on (for the record I'm an idealist with an artistic streak). What I have difficulty with is the idea that we are born into our personalities, that our character is set in stone relatively early in our childhood. Surely our exposure to people, places and experiences, our interaction with these and our ability to increasingly live in multidimensional realities stretches our persona to the limits of existential psychoanalysis