From the Stanford Encyclopedia of Philosophy

Facticity includes all those properties that third-person investigation can establish about me: natural properties such as weight, height, and skin color; social facts such as race, class, and nationality; psychological properties such as my web of belief, desires, and character traits; historical facts such as my past actions, my family background, and my broader historical milieu; and so on.[6] I am not originally aware of my facticity in this third-person way; rather, it is manifest in my moods as a kind of burden, the weight of "having to be." However, I can adopt a third-person or objectifying stance toward my own being, and then these aspects of my facticity may appear precisely as that which defines or determines who I am. From an existential point of view, however, this would be an error — not because these aspects of my being are not real or factual, but because the kind of being that I am cannot be defined in factual, or third-person, terms.[7] These elements of facticity cannot be said to belong to me in the way that the color of an apple belongs to the apple, for as belonging to me, as "determining" me, they have always already been interpreted by me. Though third-person observation can identify skin color, class, or ethnicity, the minute it seeks to identify them as mine it must contend with the distinctive character of the existence I possess. There is no sense in which facticity is both mine and merely a matter of fact, since my existence — the kind of being I am — is also defined by the stance I take toward my facticity. This is what existential philosophers call "transcendence."