Grit

"To do anything really well, you have to overextend yourself", to appreciate that, "in doing something over and over again, something that was never natural becomes almost second nature," and finally, that capacity to do work that diligently "doesn't come overnight."

Years of hard work are often mistaken for innate talent, and that passion is as necessary as perseverance to world-class excellence.

Angela Duckworth

Death

"Death anchors us in the truth. It's the signpost that takes away all illusions. Believe that you have control, and death will shatter your illusions. Associate too much with the physical world, and death will remind you that everything physical falls apart. Be proud of your knowledge, and the mystery of death will keep you puzzled. Try to slow down the decay of life, and death will crush your sense of time. When you accept the reality of death, there will be nothing left to fear. " 

Mo Gawdat, Solve for Happy