Anson Williams, 77, posts shirtless selfie with a message

Potsie Weber is officially buffer than you. Anson Williams, who played the sweet-voiced soda shop regular on "Happy Days," took a shirtless mirror selfie on Sunday and posted it to Instagram, Page Six reported.

His caption? A manifesto. "My yearly reminder to every Boomer: NEVER let anyone diminish us because of our age," he wrote. "I'm 77. More creative, healthier, busier, more curious and more alive than I was at 40."

Williams credited his wife, Sharon MaHarry, for seeing the best in him, and threw in a nod to "good lovin," kindness and adventure. He also advised a "little discipline": eat right, move, take care of yourself.

The post ended with a flourish: "Mountains still worth climbing. And the absolute refusal to let anyone else decide my worth. We didn't come this far to become invisible. We came this far to become unstoppable."

Page Six notes that fans ate it up. One commenter wrote they'd be stoked if a time traveler showed them that photo as their future self at 54. Another quipped, "Way to go Potsie!!!"

Williams played Potsie Weber on "Happy Days" for all 11 seasons from 1974 to 1984, alongside Ron Howard, Henry Winkler and Marion Ross. He later appeared on "Baywatch" and "Star Trek: Voyager." These days he's directing an off-Broadway show called "Crazy Mama: A True Story of Love and Madness."

The takeaway? At 77, Williams is not winding down. He's posting thirst traps with a side of life advice. That's a hard launch of an era we can get behind.

• Anson Williams
• boomer
• fitness
• Happy Days
• Instagram
• Potsie Weber