Since I retired
I have never worn anything except gym shorts, a T-shirt, flip-flops and a Tilley Hat or baseball cap if I'll have to be in the sun for any length of time.
If I have to go to a public place with a dress code, like a restaurant, I add jeans and sneakers (with no socks).
If I ever need to go to a formal gathering, I will try to acquire a leather sport coat with corduroy patches on the elbows.