Chasidut על יומא 57:2

Hence regarding any matter that you are coming to study, if you belittle the matter and say, "The topic is easy and readily understood" - it will already be difficult for you to access its depth; and you may even sometimes err in its simple understanding. And the Sages, may their memory be blessed, said (Yoma 29a:2), "old material is more difficult than new material." This is because one thinks, "I will certainly understand this topic easily, since I already learned it." But since he does not gird his loins and exert himself towards the matter with all of his strength; and he does not come out to truly grasp the topic, to work and to delve in it - he will not understand it. But who is the Jew who does not understand that every topic in the Torah is deep; and that when he toils and delves, he will come to the 'depths of the King' - the King of the world? And who is the Jew whose spirit does not wholly tremble to go out and meet the Ein Sof and to work in His service, to think the thoughts of God and to understand the mind of God? Certainly there have been times when after studying a nice new idea that you were enthused about, a spirit of holy jealousy came over you towards the tannaim, amoraim and the other greats and tzaddikim - may their merit protect us: Were they not also born of a woman - and nevertheless they merited to reveal so much of God's Torah in this world; they brought light to the entire House of Israel; and even in the supernal yeshiva in the supernal world, God, may He be blessed, says the law in their name! And I am a small ant; what am I worth among these lions of [God's] chariot? But why do you only suffice with a spirit of jealousy, and not want to follow in their footsteps? Please note that - with all of the greatness of their souls and their righteousness, which we cannot grasp - they toiled and worked greatly; they distanced themselves from the whole world and dedicated themselves to working in Torah. And how greatly did they toil when they studied! The Gemara (Shabbat 88a) says that when Rava was analyzing a discussion, he would injure his fingers and blood would drip, yet he would not notice. And it is said about the Ari, that even when he was studying the simple understanding of the Torah, he would stive so much that much sweat would drip off from him. But you, who are a small ant in comparison to them, do not even want to exert yourself! Hence every subject in the Torah should be weighty for you. And before you begin to study it, it should be difficult and formidable in your eyes. But it should not be so formidable for you that you give up on it. And likewise when you come to a topic that is formidable even on the simple level, your spirit should not fall and say, "This is much too hard for my brain and my grasp." Because in that way, your spirit will become lax and your intellect will become soft - and you will not work. Rather you should think, "It is a formidable topic, but I also have God's spirit and reasoning inside me. I will redouble my efforts and will be able to do it with God's help, may He be blessed."