Somebody said:
When you're 20 you worry what people think
When you're 40 you don't care what people think
When you're 60 you realise that people are not thinking.
Headgear should be:
a) Practical
b) Expendable
A baseball cap is practical because it has a peak and is cheap. So if it blows off in lane 3 on the M25 - so what.
But - it must be coordinated with your car.
Flat caps are OK but are old fart wear.
Other headgear tends to be too expensive to lose.
I have a couple of Tilleys and a straw hat but I wouldn't want to lose my Tilleys, and a straw hat looks too hillbilly.