Words of wisdom on writing and reading

Three quotes I saw on the same day. I can't help but believe there must be a connection.

I read somewhere of a shepherd who, when asked why he made ritual observances to the moon to protect his flocks, replied: "I'd be a damn' fool if I didn't!" These poems, with all their crudities, doubts, and confusions, are written for the love of Man and in praise of God, and I'd be a damn fool if they weren't.
--Dylan Thomas

Write out of love, write out of instinct, write out of reason. But always for money
--Louis Untermeyer

Outside of a dog, a book is man's best friend. Inside of a dog, it's too dark to read.
--Groucho Marx