Yeah. It requires a very complete and thorough "friendly rejection" of reality, and yourself. An overwhelming sense of "doneness", which implies some level of comprehension and deconstruction, but no resentment (because then an alternative can be suggested, and there is unfinished business to attend to). This means the fading of all of existence, relative to you, completely and entirely. There isn't even a void or anything like that. It is truly incomprehensible because there is nothing afterward to comprehend. It's the one thing that, even with all of your experience, you will never be able to predict- you can only force its necessity and the proper context, then take the leap. But even the smallest of things will prevent you from doing that, so it's notoriously difficult, and social conditioning makes it even more difficult.