I don't usually bother with entrepreneur's stories, unless they happen to include the creation of a major company. But Stephen Greer's Starting from Scrap: An Entrepreneurial Success Story coming in March from Burford Books proved to be a compulsive read.
I would say persistence. What I uncovered in my pursuit of success as an entrepreneur is that most things do not come easily and that even if all the logic stacks up behind an idea, it is sweat, persistence, and determination that make it happen.
Along the way, I often wondered if I was going to make it and felt frustrated, if not cheated, that I was not achieving the planned results. Sometimes the problems were beyond my control: employee fraud, interference from corrupt government officials, even Mother Nature. It seemed the harder I swam, the more strongly the current pulled against me. But I truly felt I was doing the right things at the right time in the right place and believed that if I could just overcome the current hurdle, it would be smooth sailing going forward. Of course it was not, but that belief gave me the strength to stay in the battle.
My hunch turned out to be correct and I was generously rewarded when our plans started to achieve success. Ultimately, a large publicly-listed company recognized the value that our hard work had created and bought us out at an attractive valuation. But I think many people would have quit before achieving that successful end result because of the pain that had to be endured to get there.
Of course, my advice to up-and-coming entrepreneurs is to strenuously challenge and test the logic behind your idea. But if you still find merit in your plans after that and believe the market will value what you are doing, be tenacious and persistent in the pursuit of your plans and goals.