Most devices I can design without much trouble now. But hand me one where a mistake could hurt a patient, or something no one has built before, and I freeze. There is no example to follow and no room to be wrong, and I sit there aware that the ones that actually matter most are still the ones that beat me.
More people experience this than they realize.
You can design most devices, but the safety-critical and novel ones still defeat you.
If this sounds familiar, the Library can help you find the bigger picture.