I have a hat like that! It’s about thirty years old, rather battered, and no longer fits on my head. So, if you saw an old guy wearing such a hat, what tribe would you put him in? I belong to a dance tribe, a music tribe, and several others. The music and dance have the most overlap. Those people wear stretchy, comfortable clothes, or ethnic colorful outfits, often with Birkenstocks. I have the Birkenstocks. However the best way to identify these people is by looking at where they hang out. There is no standard look as far as I can tell.