Take For Granted Meaning

(transitive, idiomatic, especially of a person) To give little attention to or to underestimate the value of, to fail to appreciate.

Example: 1839, Charles Dickens, Oliver Twist, ch. 17,
  Let it be considered a delicate intimation on the part of the historian that he is going back to the town in which Oliver Twist was born; the reader taking it for granted that there are good and substantial reasons for making the journey.
1946, "Posthumous Portrait," Time, 25 Nov.,
  He had fiercely championed loveless ladies entering frustrated middle age, the married woman whose husband took her for granted and seldom into his arms.