IMO, most people think of
Gnosticism as being just
this side of Atheism.
You're right. They haven't
the vaguest idea what true
Gnostics believe at all.
And I'm not even sure
Dr. Hoeller, a professed
Gnostic, is entirely sure
of the entire dogma that he
prates about.
http://www.gnosis.org/welcome.html
I'm sure that Dr. Hoeller understands historical Gnosticism very well; he is probably one of the few who do, and who nonetheless considers himself a Gnostic. The number of people who actually take real Gnostic ideas seriously, and who try to live by them, is very small, miniscule in comparison to the number of people who have read TDVC and claim to sympathize with Gnosticism.