So your frowsy old "Mrs. Jensen" (who got her B.A. in English and degree in teaching from a 3rd-rate state college, and who was, at best, a "C student") is your definitive, "go-to" source?
Regards,
You hardly know whether my English teacher was an A student or a C one, or whether or not she was “frowsy.”
But I am very, very good at punctuation, whether by school lessons or by reading excellent writers.