from the net stuff I can find about hoffman's trip it says you're right. But none of them are the original account.
I am very possibly wrong. here is some stuff I did find that relates to the idea that it is a naturally occurring substance.
http://www.uh.edu/engines/epi1037.htm
you are just as stoked about ALL psychedelics as I was before I was twenty five. I'm 45 now, and I'll probably only trip 1-4 times this year. pre-25 I was a weekly user. not better, not worse, just less focused on experimentation. Of course, I am preparing to extract some DMT pretty soon....

could just be fooling myself.