It may seem funny to say so, but you're very lucky that is hurts when you hit your finger with a hammer. If it didn't hurt you could be in big trouble.
It's a rarity when a person can't feel pain, but it does happen. Some years ago, for example, there was an eight year old boy in England who couldn't feel pain. For some reason, his nerves, did not signal pain to his brain.
If you think he was lucky, think again. The problem could cost him his life. Once he was seriously burned by a red-hot oven door, but he didn't even know it until he was snatched away.
So it is clear that physical pain can save us from mortal danger. But there is another kind of pain, too, and all of us here can feel it. It's a spiritual or moral pain, and it's called conscience. The conscience is one of our greatest gifts. Without our conscience, we would not know enough to keep from getting burned in even more serious ways than that English boy.
So as the old saying goes, "Let your conscience be your guide. " It will help you to know whether you are following the Scout Oath and Law. You have no better friend that your conscience.