I was walking down Castro Street the other day and saw a poster advertising
a support group for gay men who are HIV-negative.  Support groups are
supposed to be for people in situations unusual enough that they are unlikely
to encounter individuals in similar situations in the general community.  In
this case, being a gay man who isn't infected with HIV is so unusual that a
support group is needed so he doesn't feel like the only one on earth.

That almost sounds like an ideal group for me, except that I hate group
activities (they seem like cults), and I would be paranoid that some or all
of the members were lying about being HIV-negative.