Whenever knives are mentioned I always think of my first wife and our five years together. I met her in the middle 60s, she was a Civil Servant, 5' 2" in height, slim and I have to confess very, very pretty, and a maths wizard! She used to hitchhike alone, to and from Wales to Kent to visit her parents and she didn't like to spend money unnecessarily.
Her parents obviously were scared for her safety so I was surprised when she showed me what she always carried in her handbag when travelling, a full-blown, full-sized Bowie knife with a serrated top edge!! Her dad bought it for her and said if any car or lorry driver "tried to get fruity" just get it out and pick at your fingernails with it. She never had any trouble.
Her dad's claim to fame was that he was an engineer who worked on the first jet engine in a factory near Gloucester.
The things we remeber!
For my part, I've only ever carried a small penknife and a pair of scissors. I've never had occasion to use the knife.