In order to achieve this, Zimerman explains, he has a simple technique: that of not practising.
“Often I don’t work on a piece at home. I know what I want to do. I look at some fragments. I work on the craftsmanship, and on the piano. And then I play the piece for the first time in the concert hall. It’s very dangerous, and I wouldn’t recommend it to anybody. But for me it keeps the music fresh. The moment I start to practise something, I kill it.
Krystian Zimerman interviewed in the FT.