"Well, what if there is no tomorrow?"
Here, boiled down to its essentials, is the very basis of the movie. If you were going to live today over and over and over again for the equivalent of decades or centuries or even thousands or millions of years, what would you make of that opportunity? That is the decision which Phil must ultimately make if he wants to stop the time loop and wake up to a tomorrow.
"What would you do if you were stuck in one place and every day was exactly the same, and nothing that you did mattered?"
And here is the lesson that Phil must learn before he can get to the point in the loop at which he can enact a change. The first idea that comes to Phil’s mind upon consideration that there is no tomorrow is that it means there are no consequences. When there are no consequences for one’s action, it seems as if nothing matters. Phil must get to the point where he learns that not all consequences are immediately obvious or, indeed, ever obvious to the person who caused them because the ultimate consequence may not occur until long after that person dies. But if one could live long enough….
"I'm a god. I'm not the God."
Living long enough to see the ultimate consequences of one’s actions may easily be confused with immortality. Which is the misapprehension Phil makes. Eventually, of course, he realizes that he is not a god and that his ability to live another day—even if it is the same day—is not about immortality, but about learning a lesson.
"Anything different is good."
The motto of everyone who has been stuck in a rut. Of course, most ruts don’t last for centuries. Also, good advice for anyone who whose own Groundhog Day is not a repetition of the same day, but a repetition of the same life.
"Well maybe the real God uses tricks, you know? Maybe he's not omnipotent. He's just been around so long he knows everything."
Phil is starting to get it. That whole immortality thing and confusing it with being a god is starting to look just a little silly. Phil’s observation is particularly insightful and acutely aware of his own situation. If a person could live long enough to know more than anyone else, they could certainly appear to be a god.
