Leopard, I do agree that there is a time for a gun and a time for a knife. At night when you want to not make noise a knife can do the job. Learning to use a knife is important. Only some of us will use a knife because a knife is a very personal kill so not everyone can do it. Many will just use a gun.
But you are right that you may run out of ammo so then what do you do. Use a knife.