When I need to relax, I think about a particular beach in the Caribbean. I’ve only been there once, but it’s so profoundly beautiful that I go back to it time and again in my mind. The lush hillside above gives way to over a half-mile of clean white sand. The beach is punctuated with just enough palm and sea grape trees to give you some shade from the Caribbean sun. And the fineness of the sand extends far into the water, turning it into a turquoise blue that looks like it’s lit from beneath. Why am I telling you this? Well, because this beach is my happy place. Even though I can’t go there every day, I can conjure it up in my mind. My body doesn’t know the difference between real and imagined, so it reacts as though I’m lying on a blanket on the sand, listening to …