Generally speaking, I believe these types of tools are convenient for a lot of good reasons we can all think of. But more importantly these things are necessary for all the things we can't think of. Nobody ever showed up at a house fire with a fire extinguisher, they show up with a fire truck. The fire extinguisher is for when you did not expect the fire. Generally speaking I look at everything I EDC as an "option", if someone breaks into my house, my absolute last choice is to use a gun. But I want the option. I consider myself an intelligent person and I am sure she is too, she doesn't need the knife for the things she can imagine now, she needs the knife for the situation she can't predict, where she will want the "option" of using it. Specifically, a knife is one of those things which is tough to create at the last minute.