Medically.

It is the closest thing to death that an atheist might ever understand, in my personal opinion.

They make you squeeze that rubber bike handle thing. In three seconds, you no longer exist. You are awakened seemingly immediately. No sense of time passed like when you sleep and have a hunch how long it's been when you awake. Hours are simply erased.

The complete lack of drama is more heavy than any trip on any trendy substance, because you realize hours of your life were simply subtracted with no awareness of them passing. I can only describe it like pausing an old tape recorder for hours and then unpausing it. Maybe a coma is similar. I don't really know.

I'm here, but then I am not(and have no memory of thinking or dreaming about it). Then, immediately, I am back, being shaken by some annoying person from a stupor and feeling like shit. And vomiting later.

Well, it's sorta like that if you're a true atheist, so one would imagine. Not even any awareness of non-existence.

The good part for religious believers... if that's how things are after death, then there's no regret, because you have no thought or awareness of any kind.

If you get prodded with pitchforks for eternity, then it just meant you should have played it safer.

If you come back as a cow, then you're probably in India where all the food waste you ingest tastes like shit, because it has curry in it.

Hope the insights help a little. Hang in there.