Anaylise your piano rehearsal and practice methodically
How you think about your practice time makes a big difference. Learn to practice methodically and to make progress one step at a time. Think of practicing as saving or investing, and performing as spending. There has to be a balance between the two activities. Even a piece you have perfected will need constant care and attention.
I like to use the analogy of a brand-new car from the showroom: when you drive it off the showroom floor, it will be gleaming and shiny, the engine finely tuned and all the tanks full. After a short time, you will need to refill it with petrol, polish its windscreen and have the engine serviced. So it is with our pieces, they require constant tinkering and maintenance. If you develop a sense of craftsmanship, you will relish this work and take enormous pride and satisfaction in it.