As a youngster I frequently heard adults say to their children, "Act your age." On occasion, my own mother used that terminology on me. Most times the adult is challenging the adolescent to change the conduct they followed when they were younger. It really is a compliment to the child because they are being told, "You're farther along in life than that."
The way many people dress and act today is not an indication they are "acting their age." I've seen senior citizens with teenager haircuts and in teenager clothing. I've seen fifty-plus-year-old business people dress in styles that would be more appropriate for a teenager still struggling with how to act on their first date. Even our politicians do not "act their age" like a Harry Truman or a Dwight Eisenhower did.
Years ago you could tell grownups by the way they dressed, talked, and behaved. Now, we frequently see mature men and women wear shorts and inappropriate tops on airplanes and confuse "adult" language with vulgar language. I believe all of us who have reached adulthood have a responsibility to act and dress in appropriate ways so that our children will have stable role models.
I believe grownups have more fun and they certainly accomplish more with their lives. Think about it. If you're reading this, you're probably old enough to be an adult. Act like one, and I'll SEE YOU AT THE TOP!