Let me tell you the secret that has led to my goal. My strength lies only in my tenacity.
— Louis Pasteur

Reflection
This is also reminiscent of the Edison quote:
“I have not failed. I’ve just found 10,000 ways that won’t work.”
or the evolved saying
“you never fail until you stop trying”.
All of which is to say, the persistence is a virtue. And concurrently, any virtue taken to an extreme may also be a vice. The (misattributed) Einstein quote about doing the same thing and expecting different result, the already referenced Covey quote about making sure the ladder you’re climbing is leaning against the right structure, or the quote possibly from Will Rogers,
“When you find yourself in a hole, stop digging”.
All of which is to say, I think there’s a lot of wisdom in a lot of the quotes we’ve been exploring, and the application to ones own particular life circumstance are only knowable to the person living that life!