When you're at a party, do you suddenly feel the desperate urge to escape somewhere quiet such as a toilet cubicle and just sit there? Until I read Quiet, I thought it was just me. I'd see other partygoers grow increasingly effervescent as the night wore on and wonder why I felt so compelled to go home. I put it down to perhaps there not being enough iron in my diet. But it's not just me. It's a trait shared by introverts the world over. We feel this way because our brains are sensitive to overstimulation. I am genuinely astonished by this news. In fact, I read much of Susan Cain's book shaking my head in wonder and thinking: "So that's why I'm like that! It's because I'm an introvert! Now it's fine for me to turn down party invitations. I never have to go to another party again!"