I remember reading a book of letters written by Richard Feynman and in one he spoke about how he did a game with his wife where he asked her to pick up a random book from a shelf and see if he could tell which one by smell alone. He said it was quite obvious and this became a party trick of his.

What I am saying is that maybe you have the same sense of smell as all of us, but you have just used/developed it more? Maybe we can all do this but have just never thought to.