Going into Princeton, you know it's going to be hard. No matter where you went to high school, no matter how hard you worked, no matter how smart you are, you're going to be working really hard, and there aren't really any "paths of least resistance."
That being said, Princeton is an incredible place, and probably the best undergraduate education in the country. There is no where else where you have even nearly as much access to nobel laureates, successful businesspeople, famous lecturers or general funding as you do at Princeton.
As far as the student body, they work hard and play hard. Everyone has a lot of work, but the students really do like to have a good time, be that through engagement in extracurricular activities or a party at one of the eating clubs.
I would do it all over again, and easily would make the same decision.