I always wear a cycle helmet, never did when younger though.
As an awareness of the benefits (or so we're perceived to believe), I go along with that.
Can feel a right numpty wearing it though, but I think I prefer giving some people something to laugh about rather than potentially falling and splitting my head open on the tarmac.
The head I have might not be great, but I'd rather keep the contents of it where it should be, rather than spilling out all over the road if I were ever to have a fall.
Brian