Full Idea
Anxiety discloses Dasein as Being-possible, and indeed as the only kind of thing which it can be of its own accord as something individualised in individualisation.
Gist of Idea
Anxiety reveals the possibility and individuality of Dasein
Source
Martin Heidegger (Being and Time [1927], I.6.40)
Book Reference
Heidegger,Martin: 'Being and Time' [Blackwell 1962], p.232
A Reaction
Is sounds like insecurity, as a sort of trauma that shocks one into self-realisation. The idea means very little to me personally.