^ It does seem to be VERY VERY common. But I think it comes not so much from any discomfort like feeling you had a heart attack, but rather, from a feeling of MONUMENTAL ASTONISHMENT that what you are feeling seems IMPOSSIBLE. Once you calm down your ego's panic "oh no I am dead" alarm and convince yourself you are alive, it is a GREAT feeling.
Smoking is probably too fast to get over it and get to place where you can enjoy it, but oral dosing with the natural MAOI Syrian Rue seed you CAN have the time to OBSERVE THE TRANSITION as well as bask in the "Divine Mind Everywhere" sensation.
Here... see this, from me, from the now quiet "Chasing the experience of death" topic
http://www.bluelight.ru/vb/showthread.php?t=551751
I once became convinced I must be heading for death, doing 5-meo-DMT orally after an mao-inhibitor... here's a report:
NOTE: While I was in the midst of the below process, realizing what seemed to be happening, I momentarily had a little panic, thinking "No fucking way.... this sensation is impossible... this ***IS*** what it feels like to die... I must be dying, nothing else could POSSIBLY feel this astonishing." But fortunately I still had enough wits about me to do a little inventory. Pulse, fine, a tiny bit fast but no more than going up some stairs... blood pressure seemed fine, not popping veins anywhere... sensation every where, fine... respiration fine... I stood and walk a little and back, swung my arms, so movement and balance fine, body even felt a little euphoric in fact...
NOPE, not the slightest bit dead, silly me!
SO, I sat back down and gave in.
The magical mystery tour recipe: 3g ground Syrian Rue seed as an MAOI; after fuzzy feeling developed, 10mg 5-MEO-DMT dissolved in alcohol.
Methodically and gradually over the course of oh 15-20 minutes, everything went from being normal and still and "dead", to being totally ALIVE and whited-out with an overwhelming cosmic energy. Every atom and every stitch of space-time became imbued with a glowing vibrating awareness that was obviously the very ground of being itself.
The feeling/idea my consciousness was somehow being "created" by some mysterious electro-chemical process inside of my skull was revealed as an extreme folly, perhaps the height of human scientific egotism, a fairy tale we tell ourselves... OBVIOUSLY evolution had just worked out a sort of RECIEVER, like a radio, that captured and focused some of this.. this...
This omnipresent and eternal Meta-Awareness that was building and building, buzzing and sparkling all around me... the air, the space between the molecules, the walls, the rocks, the trees, all dissolving into their constituent atoms of "consciousness" that really made them up... not just visual, I *FELT* it, it was me, I was it. Not just light, but BEING, CONSCIOUSNESS ITSELF.
My body and skull became translucent and permeable... "I" leaked out of my skull and melded with this "All Singing, All Dancing" energy and was everyone and everything everywhere for one shining moment that lasted for ever and ever. Thus once was all that was necessary.
And the most astonishing thing about it all, when the transformation was complete, there was one and only one actual "thought" that utterly suffused it all:
Love Love Love
What did it mean? Well as I interpreted the experience - The ultimate truth? All of our awarenesses, as well as the entire physical universe is something happening inside of some One And Only primordial eternal "I", nothing more, nothing less... consciousness created it all. (Just as Alan Watts demonstrates in "The Book") Whoa.
Here's almost exactly what it felt like:
http://www.alexgrey.com/a-gallery/8-24/dying.jpg