Who am I? according to "Being and Time"

Another naively simplistic encapsulation of Heidegger in one sentence; this time his core idea of Being and Time which is pointed to in its title: Who I am (present) is possibilities (future) interpreted through history (past).

So Heidegger says of the human person, Dasein: "Its own past is not something which follows along after Dasein, but something which already goes ahead of it." (Being and Time, 1962, p.41)

Disclaimer: I am not a Heidegger scholar. Just a reader.