Yesterday is history, tomorrow is a mystery, today is a gift of God, which is why we call it the present.
The real wisdom here isn't simply that we should live in the present—that's advice as old as Socrates. Rather, Keane captures something subtler: our constant mental habit of treating the past and future as equally *real* even though we can only ever inhabit one moment. Notice the etymological grace of the final turn—"present" meaning both the current moment and a gift—which acknowledges that presence requires receiving, not just existing. When you catch yourself replaying last week's conversation or rehearsing tomorrow's meeting instead of listening to the person in front of you, you're essentially rejecting the only thing you actually possess for two things you merely imagine.