I am intrigued by the letters that subscribers write to the young generation and am moved emotionally by many of them. For half a century, I practiced pediatrics with an emphasis on adolescents and learned many life lessons from them. So many, in fact, that today I want to spin the “What would I tell the young people today” to “What would I tell young people today that I learned from young people yesteryear.” The lessons were told to me by teens. I changed the names, contributed medical and social data to prove the verity of the lessons, and published them in a book, “Messengers in Denim: The Amazing Things Parents Can Learn From Teens.” I have since retired from pediatrics and spent 10 years doing qualifying exams on military applicants. Most of these recruits were 17 to 19 years old with an occasional youth in his or her early …