Clear, in his book Atomic Habits, talks about the phenomenon "the valley of disappointment", which is the gap between your linear effort put towards something and the exponential results you gain from investing effort into that thing. The GRE is a perfect example of this: you'll often spend weeks practicing a problem type before the improvements really kick in. You don't want to quit too early or you'll miss the gains! Orion explains how he keeps his students motivated during this valley in this podcast.

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