Occasionally, people ask me questions as if I’d become the Carl Sagan of the adolescent universe. I grant that 22 years of reading 40 reflection papers from each of what now amounts to about 3,500 high-school and college students has given me perhaps a better insight into what teen-agers think than, say, a first-time parent--and surely better than the teenager, but I still have more than a few reminders of my finitude and fallibility. One of them arrived in the mail last Friday, from a group of high-school principals, asking me to give a workshop on teen-age spirituality next winter in Thcson, Ariz.