Never give up. Never surrender.

I had an opportunity to give this advice today to a young entrepreneur. The way I phrased it was "after all my years in business, seeing successes and failures in equal quantities, I believe that the greatest theme that runs through all the successes was tenacity. Those that never gave up on their dreams always reaped success. And those that failed, almost always gave up just before success was theirs." So stay the course. 'Pivot' where you need to redirect your efforts, but don't give up. Ever.

Winston Churchill is one of my favorite historical figures and I recommend reading his books - they seem never to go out of date, and his career is an excellent example of success through tenacity.