Crossword puzzle clue "wise know it all"

Wise know-it-all

Who wrote "Wise men learn more from fools than fools from the wise"

Strong poker hand ... or what the starts of the starred entries are, spelling-wise (but not sound-wise!)

You know -- know

"Someone I know wants to know (and that someone is me)"

"I know! I know!"

Sylvia Plath poem that begins "I know the bottom, she says. I know it with my great tap root"

"Demand me nothing: what you know, you know: From this time forth I never will speak word" is his last line