As explained above, the primary reason a person refrains from learning at home is because he thinks that he is not obligated to do so. This mistake can easily be refuted from a halachic standpoint by noticing that a person may say the blessings on the Torah in the morning even though he only sits down to learn at night. Although he spent many hours otherwise occupied, he does not have to say another blessing as he would on other mitzvas such as tefillin, because even though he was not actively involved in learning, his obligation to study every minute makes it impossible for him halachically to ‘take a break’. We see from this that when a person does ‘take a break’ and refrains from learning even when he can, it is clearly a transgression. Thus our Sages said, ‘just as learning Torah is greater than all the mitzvas, so the punishment for its abstention is greater than all the transgression.
ל׳ בסיון ה׳תש״פ
"והאמת בלתי שום ספק כלל, שאם היה העולם כולו מקצה עד קצהו פנוי חס ושלום אף רגע אחד ממש מהעסק והתבוננות שלנו בתורה, כרגע היו נחרבים כל העולמות, עליונים ותחתונים, והיו לאפס ותוהו חס ושלום". (נפש החיים) 1