"Did You Restart Your Computer?...OK..."

My computer wasn't working. I kept trying the same steps over and over again. Finally it worked. I guess the lesson is tenacity. On the other hand, I've heard it said that craziness is doing the same thing that doesn't work over and over again. How does one differentiate between an appropriate measure of "try, try again" and denial of the reality that something is broken and you, alone, simply don't have the means to fix it?