Or at school you might have been prodded to come “out of your shell” — that noxious expression which fails to appreciate that some animals naturally … - Susan Cain

you once said to would like to sit beside me while I write. Listen in that case I could not write at all. For writing means revealing one self to excess; that utmost of self-revelation and surrender, in which a human being, when involved with others, would feel he was losing himself, and from which, therefore, he will always shrink as long as he is in his right mind...That is why one can never be alone enough when one writes, why there can never be enough silence around one when one writes, why even night is not night enough.

As a young boy, Charles Darwin made friends easily but preferred to spend his time taking long, solitary nature walks. (As an adult he was no different. “My dear Mr. Babbage,” he wrote to the famous mathematician who had invited him to a dinner party, “I am very much obliged to you for sending me cards for your parties, but I am afraid of accepting them, for I should meet some people there, to whom I have sworn by all the saints in Heaven, I never go out.”)

Upbeat tunes make us want to dance around our kitchens and invite friends for dinner. But it's sad music that makes us want to touch the sky.