From the book “Grit” by Angela Duckworth

“​In sum, no matter the domain, the highly successful had a kind of ferocious determination that played out in two ways. First, these exemplars were unusually resilient and hardworking. Second, they knew in a very, very deep way what it was they wanted. They not only had determination , they had direction. It was this combination of passion and perseverance that made high achievers special. In a word, they had grit.”