Trying to make up meatier sentences about writing than Updike has already provided being presumptuous for most and stupid for me, I'll just pass along a few from his obituary:
"It's always a push to get up the stairs, to sit down and go to work,” he told Time magazine in 1982. “You'd rather do almost anything, read the paper again, write some letters, play with your old dust jackets, any number of things you'd rather do than tackle that empty page, because what you do on the page is you, your ticket to all the good luck you've enjoyed."
That Updike can calmly bare the mortal weaknesses many might have in common with him only accentuates the very uncommon talent that he flourished:
There's a kind of confessional impulse that not every literate, intelligent person has,” Mr. Updike said in his 1990 Globe interview. “A crazy belief that you have some exciting news about being alive, and I guess that, more than talent, is what separates those who do it from those who think they'd like to do it. That your witness to the universe can't be duplicated, that only you can provide it, and that it's worth providing.”