I had the same grandfather and tell a very similar story, or bit of folklore now that I am contradicting my sister, your mother.  He was walking on an icy day the winter he was 92, with his hands in his pockets, slipped, face planted and broke his nose.  So, take your hands out of your pockets.   The Real Lesson in this is not don't walk with your hands in your pockets it IS everybody remembers the same story differently.  Sounds like a writing assignment.  (The rest of the story gets involved with the gentleman who felt so very sorry for him and didn't know if he had any family or not and had worried about him to the point of driving his extended family nuts.  One day when I was at my best friends house for the afternoon, well, of course it turned out that my best friend's father was worrying about my grandfather.  An,yes, everyone lived happily ever after.)