Grit: The Key to Success

Angela Lee Duckworth left a high-flying job in consulting for a more demanding job as a 7th Grade Maths teacher in a New Yourk public school.  Then, she left the classroom to go to graduate school and study the best predictor for success in students, rookie teachers, West Point Military Academy cadets, competitive sales people, and she found that the best predictor for success was not social intelligence, good looks, physical health or IQ, it was grit.  Grit is "the passion and perseverance for very long-term goals", it is "having stamina". "Grit is living life like it is a marathon, not a sprint".
This short TED Talk video (06:12) with subtitles can be seen by B2 learners.