The Gemara (Brachos 63B) says that Torah will only last if a person “kills himself over it.” This is learned from this verse: “This is the Torah: If a man dies in a tent...”
Sefer Chashbah L’Tovah explains that the Gemara obviously does not mean that one should literally kill himself, as this is clearly forbidden. Rather, Chazal’s intent is that one has to kill his “self”. One must kill his own ego in order to succeed in learning Torah.