We are talking about waiting. The time between when you start and when you reach a level of useful proficiency is time you wait through. You don't wait doing nothing, but you certainly do wait. Yes, it's not a useful way to frame the situation, but that's what makes impatience a flaw. If an impatient person could distract themselves from how much longer the task will take and concentrate on actually performing the task they would not be impatient, they would be a normal person coping with the impatience everyone feels.