The Piece Of Advice Brian Dietzen Would Give His 18-Year-Old Self

Brian Dietzen thought he was going in for a one-episode cameo as Dr. Donald "Ducky" Mallard's temporary assistant on "NCIS" in 2014, but he did such a good job, he became a permanent part of the popular show starting in season 10 and continuing through into season 19, the current season (from Hello!). And he recently got the chance to branch out beyond playing Dr. Jimmy Palmer on the show.

Dietzen shared a pic on Instagram holding the script for episode 13 of season 19 and wrote "You guys, I got to write a script of ['NCIS'] with my pal [Scott Williams] and it's been a great adventure so far. We jump into filming this bad boy after the Thanksgiving weekend, and I couldn't be more excited. It's my first time writing for the show, and it's been a great experience."

While currently a mainstay on "NCIS," the 44-year-old Colorado native had his first big-screen part in "From Justin to Kelly" in 2003 (from IMDb).

After his time on stage and on screen and just overall growing up, he has some advice for his younger self.

Brian Dietzen's advice to his younger self is echoed by other celebs

When asked by UPROXX what he'd go back and tell his 18-year-old self, Dietzen had some sage advice: "Don't hurry too much. You have your whole life to be a grown-up. And don't beat yourself up for making mistakes. They happen to everyone. Often. 90 percent of success is just showing up. With pants on. Wear pants if you're going to a meeting."

Seems like a mix of good advice with a twist of humor to it. And other celebs have had similar advice for their younger selves. George Clooney would have told himself to have "patience because that's always the thing you don't have when you're young because you think everything has to happen immediately" (via InStyle).

And Michelle Obama's onboard with making mistakes, telling People, "Understand that no one — especially folks who are truly successful — simply coasts from achievement to achievement. The most accomplished people in the world fail and fail big."