Blow Someone's Mind Meaning

(idiomatic) To astonish someone, to flabbergast someone.

Example: 1974, Barry White, Can't Get Enough of Your Love
  How can I explain all the things I feel?
  You've given me so much
  Girl, you're so unreal
  Still I keep loving you
  More and more each time
  Girl, what am I gonna do
  Because you blow my mind.