They're very different imho. Pages are beginnings, young, immature, innocent, the optimism of youth (which you can have with 80, too) - you start something new, you have the rookie bonus, you don't know how something works. You're the learner (you or the person the card relates to - sometimes the court cards just catch the spirit of a situation but most of the time, they relate to people). The Page is the young boy starting to wash the brush and bucket of the master, bringing the beer and waiting for his turn to learn something.
The Knight is like a journeyman - he is much more mature, self confident, and competent. But he's not a master yet, and he's not ready to settle down. (Sorry for the many male metaphors - I could have used feminine ones, too, but in order to keep it short, let's stay with the masculine). We are Knights when we go out into the world in order to try what we have learned. We ride through the world with out knowledge and toolbox, and we are learning now how things really work. We don't have the optimism of the Page anymore - we know that the world can be unfair, that we can fail or that others can spoil our party. But we press on. We're on our way to the throne of mastery, of unchallenged authority, the place where we can sit down and take control of our fate (and since human life is the way it is, we never sit on that throne permanently - we start new cycles and turn into pages again when new chapters of life wisdom are about to be learned).
The Page of Cups is an innocent, freshly-in-love puppy who can see only wonderful things in the person or subject that enchants him/her. The Knigh of Cups is aware of his/her charm and charisma and uses them in a much more self-conscious manner.
The Page of Wands is enthusiastic about an idea or a project that's still in the planning stages, while the Knight runs the show and organizes everything.
The Page of Swords plays with new ideas and plans, with very basic but interestingly original analysis and the understanding that every problem can be seen and discussed from different angles. The Knight of Swords knows exactly what he/she's fighting for and rushes happily into battle.
The Page of Pentacles is just starting to take responsibility, and put ideas into practice. The Knight of Pentacles is a hard worker who will take on all the responsibility and will take care to see a project through from start to finish, tying all the loose end patiently.
They're really very different. Whenever you learn something new, you're a page. Whenever you know something well enough to prove it to yourself and the world, you're a Knight.
The Queen means that the learning stage is over and the lesson has been internalized. The King is able to lead and teach others. They're our mature selves - assertive and less flexible than the earlier stages. In the queen stage, there is often quiet inner joy that doesn't need any outside feedback or proof - you just know what to do. And in the king stage, this is not enough and we seek recognition for our abilities. That's when the danger of a certain rigidity becomes too strong - and some Page innocent questions should come up to burst our bubble
That's how I have come to see the court cards. When they're not stages in personal development, they're the energy around a situation project idea relationship....