Earlier quoted context omitted.
At the risk of being pretentious, I would say that what we all yearn for is (Heidegger's idea and vocabulary): "spatio-temporal ecstasis" -- the feeling that our self is expanding into the world, quickly and far. I get it when I learn more math -- I can feel my power or whatever it is expand into world. Teens in a good environment get it when they do their homework -- they know they are expanding and they feel it. Al…
The classical notion of ecstasis is to be outside oneself, as in the phrase "beside oneself with joy". That's very different from inhabiting an expanded self. Are you saying that Heidegger revised the classical notion? If so, did he do this as part of an extended critique? Nietzsche was a classicist and Heidegger's whole philosophy (if I remember grad school) was about taking off from classical roots, so it's unlikel…
Heidegger didn't really believe in a transcendent self, as far as my very amateur reading can tell. Rather, I think he was critiquing all things transcendent (yeah, Plato and Kant), and trying to show how things and experience would feel transcendent, even if they aren't.
I also think he used a lot of irony -- he talks about authenticity, and he sort of means it but he also sort thinks that any personal transcendence is just balderdash; so authenticity is facing both death and the lack of any final answer as to what is authentic. (All that a Dasein "is" is something that wonders what it "is". This self-questioning of being, or "is-ness", of both the world and ourselves, is fundamental to the human condition, and is where the "Being" of "Being in Time" comes from.)
Re ecstasis: He was talking about the phenomenological experience of interacting with the world. And I interpret "ecstasis" to mean "the process of expansion into the world" -- sort of getting outside one's "self", but with a sort of ironic notion of selfhood. Again, there is irony and allusion to the classical notion, but recast in his own phenomenology.
My rather loose interpetation of Nietzsche is that supposedly nietzschean self assertion is not really Nietzschean at all, but rather naive and foolish and immature. Zarathustra counsels against going to the city and indulging in pleasure.
YMMV -- I am just a guy talking in a bar about these things.