I was at the store today and some old guy came up and patted my helmet kind of firmly and said "Thank you for wearing that"
My initial reaction when I saw a hand grabbing at my helmet was WTF WHO IS GRABBING MY SHIT
I kept calm and then he told me how he'd be dead if he hadn't had his helmet on, and that he was in this horrific accident, and killed his neighbor and suffered brain damage, cracked his helmet open he said. He didn't elaborate on the story but the guy looked like he was in a bad wreck at some point.
He also told me he crossed the country 9 times over his life. Cool guy.