Jackson Browne gave us that advice. He would rather have you explore.
Exploring helps you figure out what you can do the next time you present or perform or interact. Rehearsing, on the hand, means figuring out exactly what you're going to do so you can protect against the downside, the unpredictable and the embarrassing.
I'm not dismissing study, learning, experimenting or getting great at what you do. In fact, I'm arguing in favor of this sort of hard work. No, I'm talking about the repetition of doing it before you do it, again and again. Just drilling it in so you can regurgitate later. Better, I think,as they say, "…let's do it live."
A well-rehearsed performance will go without a hitch. An explorer seeks the hitches, because hitches are the fissures and chasms that help us leap forward.