Difficulties break some men but make others. No axe is sharp enough to cut the soul of a sinner who keeps on trying, one armed with the hope that he will rise even in the end.

Persistence is very important. You should not give up unless you are forced to give up.

The thing about inventing is you have to be both stubborn and flexible. The hard part is figuring out when to be which. If you're not stubborn, you'll give up on experiments too soon. And if you're not flexible, you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve.

I accepted that if you have a problem, you must face it and not gloss over it.

Be persistent and resilient in the face of challenges, for they are the building blocks of success.

Do Something. If it works, do more of it. If it doesn't, do something else.