Grit is passion and perseverance for very long-term goals. Grit is having stamina. Grit is sticking with your future, day-in, day-out. Not just for the week, not just for the month, but for years. And working really hard to make that future a reality. Grit is living life like it’s a marathon, not a sprint. – Angela Duckworth
Grit is derived from self-knowledge:
Knowledge of what you want, truly.
Knowledge of your natural skills and abilities, and how to best deploy them.
Knowledge of your weaknesses and gaps, and how to make them irrelevant (or convert them to strengths).
Knowledge of the pitfalls and obstacles and difficulties you will face, and having a plan and measures in place to deal with them effectively.
Knowledge of how to develop strength, and endurance and flexibility, in a way that works best for you.
Knowledge of how things work, both for you and the World.