I’m only about ten years late to reading The monk who sold his Ferrari, but this quote stands out:

“If you care for your mind, if you nurture it and if you cultivate it just like a fertile, rich garden, it will blossom far beyond your expectations… Yet look at the toxic waste most people put into the fertile garden of their minds every single day: the worries and anxieties, the fretting about the past, the brooding over the future and those self-created fears that wreak havoc within your inner world.”