And suddenly I realized that I was addicted to Nitrous Oxide. They had said nothing about addiction in the books. But I had been doing it every day for about 6 weeks, maybe more - and had been doing it excessively before it became daily. And when it ran out I just could not cope. This was not a drug withdrawal like an opiate - this was madness incarnate. I could not *stand* being in my body - it was blindingly intense and wouldn't go away.
Nitrous for me is like a shortcut to ego death, exactly as you described it. Absolute understanding, and as soon as I come back all I can conjure up is "infinite" or "it's all the same". It feels like it's trolling you because for a moment you truly understand how utterly meaningless everything you've experienced in your life is, you dip back into the infinite. And as soon as you remember yourself, your ego, that feeling/knowledge is tantalisingly out of reach.
With me, as with every other person of whom I have heard, the keynote of the experience is the tremendously exciting sense of an intense metaphysical illumination. Truth lies open to the view in depth beneath depth of almost blinding evidence. The mind sees all logical relations of being with an apparent subtlety and instantaniety to which its normal consciousness offers no parallel; only as sobriety returns, the feeling of insight fades, and one is left staring vacantly at a few disjointed words and phrases, as one stares at a cadaverous-looking snowpeak from which sunset glow has just fled, or at a black cinder left by an extinguished brand.
Whipped-cream chargers contains no oxygen. Oxygen deprivation that can cause brain injury and suffocation can result from lack of oxygen from pure nitrous oxide continuously inhaled from strap-on mask connected to a gas canister. Never use nitrous in any manner that does not provide for adequate oxygen intake. Suffocation can occur without discomfort.