LOS ANGELES — Trees are turning red and orange, and public pools are no longer turning yellow. Fourth of July junk is no longer clogging department-store shelves, replaced instead with shamelessly premature Halloween junk.

It can all mean only one thing: The lazy days of summer are drawing to a close, replaced once again by hectic school schedules.

Have you ever heard the phrase, "If you can read this, you should thank a teacher"? Well, somebody had to teach all those Hollywood superstars how to read their highfalutin scripts, so as school comes back in session, they too feel the need to give shout-outs.

"Growing up in Dallas, I had a great teacher named Mr. Adams at St. Mark's," Owen Wilson recalled of his high school days. "He was a history teacher, and both my brothers had him. He was just a great teacher who made you excited to go to class, and for me — who was not a good student — that was a pretty remarkable feat."

"Judy Weldon," Rachel Bilson said, not missing a beat when asked to name her favorite teacher. "I haven't seen her in awhile, but I grew up here in Los Angeles, so she's around. She was my drama teacher. She was very inspirational, and she definitely got me into acting. I'm so grateful to her for that."

"Hyacinth Young," said Kate Hudson, insisting that a chance pairing with a teacher shaped both her character and her career. "She was a high school teacher of mine — my voice teacher, debate teacher and English teacher for two years. That was very rare in my high school, to have a teacher that much, but she was really the first person to introduce me to my love of literature. Still, to this day, I think about her all the time."

For some celebrities, the greatest lessons are those that take them down a peg.

"Miss Bender, my science teacher — I got busted doing the mirror-on-the-shoe trick," laughed Mark Wahlberg, a notorious troublemaker back in the day who clearly wasn't above trying to sneak a peek up a teacher's skirt.

"She was kind of cute — I think it was in eighth or ninth grade," the "Invincible" star recalled. "[She taught] science, but I don't remember any of it. I don't remember a thing, but I remember her."

"The teacher that I remember, I really didn't like too much," said Matt Dillon. "He wore clogs, and he had a perm and a really oily mustache. I didn't like that guy too much. But I find that I've learned more from failure than from success. Isn't that interesting?"

Sometimes you can learn as much from an F as from an A. And sometimes life's most influential teachers aren't necessarily drawing paychecks for their efforts.

OUR NEWEST TRAILERS
Check out "Pan's Labyrinth," two trailers for "Curse Of The Golden Flower," "Fur" and more, on Overdrive

"Who was my teacher?" Nick Cannon said. "My grandmother. She taught me the difference between right and wrong, so that has been with me from the very beginning, and my grandmother really don't play.

"[There were some] tough lessons to learn, but I learned 'em, and I've got the scars to prove it," the "Wild 'N Out" mastermind added with a laugh.

Cannon's mentor is still ready to teach a lesson if her grandson's head gets too big. "She's probably gonna call me about how I was saying she's been whooping on me," he said. "Every interview I do, she's always saying, 'I don't appreciate how you're up there talking about me. That don't make no kind of sense — you ain't learned nothing.' I can hear her now."

"I've learned the most from having conversations with people waiting around to do whatever they were waiting to do," said "Hollywoodland" actress Diane Lane, noting that people can encounter life-altering teachers in the most random of places. "Waiting in line, waiting in the trailer to shoot, having heart-to-heart conversations about a life story — it's those candid, casual moments when I get to have an honest question-and-answer session, when it's not being filmed, where I've had the best teachers."

"I had an aunt who gave me three pieces of really great advice about men — she was a really good teacher," said actress Robin Tunney, who also appears in "Hollywoodland." "Her advice was to never go out with a guy who wears cologne that you can smell. Never go out with a guy who drives a Corvette, new or old. And never go out with a man who, when you walk by a mirror, looks in it before you do. I've followed that advice, and it's worked really well for me."

We learn all kinds of lessons in life, and there are teachers all around us. Now that school is back in session, it might be time to make like a movie star and thank your greatest teacher.

Visit Movies on MTV.com for more from Hollywood, including news, reviews, interviews and more.

Want trailers? Visit Movies on MTV Overdrive for the newest, scariest and funniest coming attractions anywhere.