“The definition of insanity is doing the same thing over and over again and expecting different results.” – Various

“Love of bustle is not industry.” – Seneca

“Jack of all trades, master of none.” – Various

“I know only that I know nothing.” – Socrates, paraphrased.

“The unexamined life is not worth living.” – Socrates, Plato’s Apology

“Know thyself.” – Ancient Greek aphorism