From David Markson's novel Wittgenstein's Mistress.

Though it fact perhaps it was Kierkegaard who said that, about anxiety being the fundamental mood of existence.
If it was not Kierkegaard it was Martin Heidegger.
In either case I suspect there is something ironical in my being able to guess that something was said by Kierkegaard, or by Martin Heidegger, when I am convinced that I never read a single word written by Kierkegaard or Martin Heidegger.

In the novel someone, who is apparently the last person on earth, travels about Europe, visits Troy, sleeps in museums, and prattles on.  ¶ 6:42 AM