At the end of Groundhog Day, absolutely everyone in Punxsutawney adores Phil Connors and treats him almost as the town's favorite son... despite the fact that his recent outbursts of philanthropy and goodwill aside, from their perspective he should still be a relative stranger who has been in town one day tops. At first, it seems that this is a reflection of his new likeable nature requiring Willing Suspension of Disbelief... until you remember that earlier in the movie, one of the selfish things that Phil did with the "Groundhog Day" Loop was use the information he gleamed about the various townspeople he met in order to manipulate them to do what he wanted them to do, often by pretending that he was someone that they knew in their past but had now forgotten. By the end of the movie, he's learned so much about them and the town that it's not inconceivable that he could easily integrate himself into the fabric of the town even over one day by 'reintroducing' himself to a few select people and claiming to be someone who used to live there a long time ago and has now returned, hence their shaky recollection of him — only now, he's doing so in order to enrich their lives rather than merely enriching himself.~ Doctor Nemesis
It was cut from the movie, but he had been in the loop for several years by the time he escaped, so the above is even more likely.
There's some deeper stuff going on in this movie. Punxsatawney Phil, the groundhog, is a little rodent hiding in the winter and refusing to come out until he can't see his shadow — his "dark side", if you will. Phil Connors is a metaphor for the groundhog (or the other way round) since he, too, is isolated in Punxsatawney — his knowledge of the town's inhabitants in a way makes him Punxsatawney Phil. He, too, is refusing to come out from hiding in the town's winter until he can't see his dark side — i.e. that his dark side has been eliminated. More to the point, there's also a strong Messiah thing going on. Phil Connors, half-mad, says that's he's God — not the God, but a God. And yet... by the end of the film, he has almost omniscient knowledge of how events will go. He's become tremendously compassionate, running from one place to another to make people's lives better, being in the right place at the right time. He even tries to save a dying man's life... and yet he can't stop any of these events because they're pre-ordained or because people retain free will and can refuse his actions. He's part of the system, he can influence it, but he ultimately cannot change it. Phil might not be The God, but he probably knows how God feels.
Aside from being unable to save the one dying guy, what was Phil not able to change?
How about the snowstorm?
Not to mention human nature itself.
Also, even if Phil was able to change a lot, he's still just one man. And he had only one DAY. And even the most accomplished, skilled, and proactive man is only capable of so much in a single day.
Having just saw this movie again the other day, I noticed that at the end Phil Connors makes a suggestion about moving into town with his new girlfriend. The part that caught this trooper's attention was him suggesting that they start out renting. It then occurred to me that the reason he wants to start out renting is that he's not fully sure he's out of the loop. He knows he has managed to get to the next day, but what if he has to relive this day over and over again. Until he knows that he is actually done looping days, he really isn't ready to commit to change.
No, he suggested renting because he remembered that as far as Rita's concerned, they've only been together one day (and she's only known him for two). Did you miss that part? Suggesting that they buy a house implies a marriage proposal, which would spook her.
Of course, he might not have the money to make a down payment on a home anymore: he did just buy A LOT of insurance!
However, if he robbed the armored truck like he always did, then he would have tons of money. I initially thought that new Phil probably wouldn't continue to rob the truck, but then we hear from the piano teacher that even on that final day, he had taken lessons from her, and if you recall correctly, she already had another student that day, and only worked with Phil because of the money, so he had to have done it again on the final day.
If he robbed the armored truck the final day, then there would have been an investigation which could implicate him - he doesn't get the reset to avoid it.
His piano lessons were costing $1000 each iteration (but he got that money back at 6 AM anyway). In the end, he's down $1000 which he might have had on him before the time loops started. He is a celebrity in an emergancy, after all.
He may not have actually had the piano lessons on the final day. She said that he was her student, but he may have just convinced her that she'd taught him years ago.
It's more likely he only bribed the teacher the one time, then learned the schedule and took lessons when the kid's lessons were over. Since he can time just about everything, waiting for the teacher to be free isn't a stretch. Plus, he probably didn't get a lesson on the final day, since he didn't need it anymore, and instead stopped by to thank the teacher and acted like an old student.
If he robbed the truck on the final day, he wouldn't have improved himself, so he wouldn't have broken the loop. And it's likely he only did that a few times before deciding to better himself.
Then again, it could be that he only wants to rent because, although he's no longer a Jerkass and has become a genuinely nice guy, he's still Phil, and he isn't necessarily sure that he wants to spend the entire rest of his life in frickin' Punxsutawney.
A few pointers of Fridge Brilliance as to why Phil wants to buy a house in Punxsutawney, but then hedges by suggesting they rent. Firstly, from his perspective he's probably lived there longer than he's lived anywhere else in his entire life by this point, if not longer than the entire rest of his life put together; it's become more of a home to him than anywhere else. Secondly, if he is out of the time loop, he's probably going to have to spend a bit of time getting used to not being able to know what's going to happen and knowing everyone and everything around him intimately — which is probably going to be easier in a small, fairly safe and quiet town like Punxsutawney than in a large metropolis like Pittsburgh, where a random brain-fart could see him run over by a bus or something. And thirdly, similar to what the troper above suggests, he's spend so long in the confines of the loop and the town that he's probably a bit wary of the wider world by this point, but with his zen-mindset by this point he knows he can't keep those hang-ups forever; he knows he has to move on at some point. He's not quite ready to let go of Punxsutawney yet, so he suggests buying the house, but changing it to the option of renting is allowing for changing his mind or letting Rita persuade him otherwise. And finally, he suggests buying the house in excitement, but then realizes it probably sounds a bit weird and overwhelming for Rita to be asked to move in with someone you've only met two days ago from her perspective; he initially doesn't realize this because from his perspective he's intimately familiar with her, but he amends his suggestion once this occurs to him.
I think Phil and Rita have known each other for a while, not counting the whole Groundhog Day Loop. From her point of view she's just seeing a side of him she's never seen before.
Actually, the early part of the movie establishes that Rita is a new producer on their show, and that she and Phil have never spoken before going out to Punxsutawney before.
There's a double meaning when Phil yells "See you tomorrow ... maybe," to the Little Brat who never thanks him for being caught after falling out of a tree. The first meaning, of course, is "maybe the cycle of repeats will have finished tomorrow." The second meaning, however, is "if the day does repeat, maybe I'll just let you fall and crack your spine or something just to teach you a lesson."
The second meaning you mentioned is the one that seemed obvious to me, not the first.