In Brat: An ’80s Story (Grand Central, May.), the star of Pretty in Pink, St. Elmo’s Fire, and other seminal 1980s movies reveals the psychological conflicts that plagued him.

You write that when Molly Ringwald wanted you as her romantic lead in Pretty in Pink, producer John Hughes said, “WHAT? That wimpy guy?” Were you as surprised as he was when you became a heartthrob?

Completely. That part was written for a jocky, square-jawed quarterback type, and I did not fit that mold. I was shocked by how things took off.

Your movies from the 1980s feel very different from today’s coming-of-age movies, which all have teens battling evil empires in postapocalyptic hellscapes. Why did they catch on?

I think my movies gave young people credit for having rich emotional lives that were worthy of respect and exploration, trying to navigate relationships and proms and growing up. That’s perfect for movies. I have an 18-year-old son and, my God, his emotional life is so intense.

You sometimes seemed to have more inner turmoil and awkwardness than your characters, especially at a casting meeting that almost lost you the part in St. Elmo’s Fire. Were you sabotaging yourself?

That’s the nub of the book: all of us have fears and doubts that can sabotage us, that paradox of wanting something yet also wanting to retreat. At that meeting they were just trying to get me to say something, anything, but when I would get fearful I would withdraw. I’ve never been good at selling myself, because it feels so transparent and false and I didn’t think one should have to. They drove me to the meeting in a stretch limousine, but I did so badly that they drove me back in a little Volkswagen.

How did your alcoholism affect your work?

Drinking usurped it for a time. I loved going to work, but if you’re hung over you’re not going to be as good, whether you’re bagging groceries or acting. Alcohol’s a cunning foe that sneaks up on people: drinking caused me anxiety and the remedy for that is to drink, and round and round you go. I don’t think my acting success caused my alcoholism; without that I would have just drunk cheaper vodka.

You were lumped in with Emilio Estevez, Judd Nelson, and the rest in the Brat Pack. Blessing or curse?

Like much in movies, the Brat Pack had little to do with reality. I haven’t seen either of them since the day we finished St. Elmo’s Fire; we did a job for eight weeks together, then we’re linked together forever in cinematic lore. That name gave us a profile that was both limiting and expansive. It was originally leveled in a pejorative, nasty way, but it’s become a nostalgic term for that generation’s ultimate in-group. It’s something I wrestled with for years, but ultimately I decided, “Yeah, sure, why not?”