The Rogatchover Gaon once related that the most difficult day of the week for him was Shabbos. During the week, when great waves of thoughts and insights flooded his mind, he always had the opportunity to write them down. Putting something in writing confines one's stream of thoughts, making it easier to come to a conclusion regarding the issue at hand. As he was not able to do this on Shabbos, he had to toil greatly in order to reach some type of clarification.
Each and every one of us has the opportunity to choose whether material burdens such as earning a livelihood should dominate our lives (in which case our thoughts rob us of peace of mind), or whether to exchange this burden and toil for a more spiritual and gratifying burden, the toil of Torah study. In the latter, one toils so much that he is overwhelmed with one insight versus another to the degree that he struggles to resolve the two.
Likkutei Sichos, vol. 1, p. 117