In his late 50s, my Dad took to riding my old BMX to the centre of town and back. He made for a somewhat incongruous sight as he, I kid you not, would often be wearing a flat cap, combined with a tweed jacket while smoking a pipe.
One day, some of the local yobs thought it would be a good idea to try and mug him. My Dad immediately pulled out an extendable cosh and offered to take them all on. They fled. His only regret was that he was no longer fast enough to catch them.
I guess they learned a lesson that day. Sometimes even the most unlikeliest looking people have had several decades of martial arts training.