I started castrating calves on our farm when I was about 11 years old, you have to be fast, and have the nerve for it, and a sharp knife is a must. I never got into the butchering, in the fall. Either way, a knife played a crucial role in putting meat on our table.
Filet mignon.... the psoas muscle, my favorite, most tender cut. Mostly flexed in us bi-peds, mostly relaxed in the quads, hence the tenderness. And, yes, I have dissected it, in both.