For a person to properly apply himself to learning Torah he needs to feel three things:
- That he has only one more day to live.
- That he has to learn only the daf or Mishna he is presently learning.
- That he is the only Jew in the world, and Hashem commanded him to learn Torah.
The benefit of this is that by thinking this is his last day on earth he will not procrastinate, pushing it off for tomorrow. By thinking this is the only thing he needs to learn he will negate the evil inclination’s claim that learning the whole maseches is too hard. By thinking he is the only Jew in the world he will feel that if he doesn’t learn now the world will cease to exist, thereby rebuffing the evil inclinations’ assertion that surely there are other Jews learning right now somewhere in the world. So our Sages directed us to always consider the world half righteous and half wicked, and by doing one good deed he tips the scales of the whole world.