We have learnt in the Mishna “Woe to the creations from the disappointment of Torah”. The Meforshim explain, that one who learns Torah is compared to a person who is told “count the gold pieces and whatever you manage to count, you may take for yourself.” Such a person will certainly not tire or become weary from counting and will continue all day and all night. If he becomes lazy and does not count, he is disregarding the gold and showing that they are unimportant in his eyes. The exact same idea applies to the Torah.
Even if a person would study all day and all night and would want to be available for half an hour to waste time, to occupy himself with jokes or empty things and to be amongst those who sit in the corners, (the fact that he studies all the time) will not release him from judgement. Rabbi Yishmael said to his nephew who asked him if after he had studied the entire Torah he would be permitted to study Greek wisdom. He replied to him “the verse says “and you should speak about it by day and by night”. Go and find a time which is neither day nor night and study Greek wisdom in it.”
Our Sages have already said that all troubles and bad things that come to the world, whether to the general population or to the individual, as well as the delay in the coming of Moshiach, all of these are due to the sin of wasting time from studying Torah.