Walnuts are good for you. But if you buy bags of shelled walnuts, you’re paying extra and it’s too easy to eat too many. Buy them in the shell and then, well, real dudes don’t use nutcrackers. My favorite way to open one is to cradle it in the finger-cradle just above my palm and then SLAM that nut down on a hard surface. This works about four times; by then my nervous system has noted that my hand hurts, and I just won’t let myself slam hard enough again.
You can poke a walnut open with any semi-sharp object, even a fork. The stem-point is a great weakness in the walnut-shell fortress. But what could be more fun that squashing two walnuts together in your hand? Usually one is harder than the other, and the other cracks. Then just imagine all the calories you expend picking the nutmeats out of the debris!