Just don't look in the mirror.
I never used to wear one unless I was racing as you had to. The last few years I've worn one due to peer pressure and comments from the local cycling club im in, not as a fashion accessory but from a safety point of view.
My view is that if you get hit by a ton and a half of car or worse, a bit of polystyrene on top of your head wont do too much to alleviate the symptoms. OK, it might prevent head injuries but mostly you come down on your face if that's the way you're falling. I've had a few crashes in 30 years of cycling, memorable ones being going through the back window of a car in front (at speed, helmetless) and being rammed form behind (also at speed) by a car driver who was not looking where they were going. Collar bones and pelvises are the most common injury.
These days, I just wear the lid,,,,, and don't look in mirrors.