Let’s address the elephant on the beach. The mature individual has rejected the "mumu" just as firmly as they have rejected the micro-bikini. The updated aesthetic is : practical, sun-safe, and elegantly draped.
Pack the large umbrella. Bring the good cheese. Download the audiobook. Walk into the water up to your waist, float on your back, and look at the clouds.
Drive-in movies are back, but now they happen on the sand.
Boxed wine and soggy sandwiches are out. The updated lifestyle prioritizes gastronomic picnics.
Maturity brings a glorious honesty: you no longer feel obligated to be "on." You don't need to impress the couple next to you. In fact, you’ve likely reached the stage where you actively enjoy the silent pact of shared solitude.