Endurance

"I know quite certainly that I myself have no special talent; curiosity, obsession and dogged endurance, combined with self-criticism, have brought me to my ideas.”

-- Albert Einstein

Intelligence

"It's not that I'm so smart, it's just that I stay with problems longer."

-- Albert Einstein

Insanity

"The definition of insanity is doing the same thing over and over and
expecting different results."

-- Albert Einstein