Why does Pip cry?

Pip cries when he thinks about the reasons he avoids Joe.... Estella's contempt.

Then I thought if she were, as I feared, by no means rapturously grateful for that destiny yet, when would she begin to be interested in me? When should I awaken the heart within her that was mute and sleeping now?

Ah me! I thought those were high and great emotions. But I never thought there was anything low and small in my keeping away from Joe, because I knew she would be contemptuous of him. It was but a day gone, and Joe had brought the tears into my eyes; they had soon dried, God forgive me! soon dried.