I'm 59 1/2 years old, with many many more years left for powder and trees.
I've been wearing a helmet for several years now and can think of two times that I was very glad to be wearing one. Both times, I simply washed out my heelside edge and went down hard on icy snow on my back with a hard hit to the snow with the back of my head. Helmet really made a difference in these cases. Once in Utah and once in Colorado.