Uniqueness isn't one dramatic trait. It's a long list of small ones that has never appeared in this combination before: the streets you know shortcuts through, a joke only four people alive would get, the exact year a song came out and where you were standing.
Nobody else carries that particular inventory. Not because you're extraordinary — because the list is long and the arrangement is unrepeatable.
The pressure to be special in some visible, rankable way misses all of this. You already are the only person running this exact set of memories, and there is no way to stop being it.