You do not cross into it whistling

"If you live in the dark a long time and the sun comes out, you do not cross into it whistling. There's an initial uprush of relief at first, then-for me, anyway- a profound dislocation. My old assumptions about how the world works are buried, yet my new ones aren't yet operational.There's been a death of sorts, but without a few days in hell, no resurrection is possible." 

-- Mary Karr, from Lit: A memoir