The Western and the liberal consensus on Joseph Stalin:
Stalin was an evil autocrat who seized all power from his people to establish a brutal and murderous authoritarian regime.
Stalin in reality
Stalin: Please, let me resign in peace. This is the fourth time I am submitting my application.
The central comittee: Dear Comrade Stalin, we have rejected your request for the fourth time. See you at work tomorrow.
Positions of power & leadership are stressful. He was probably just tired of it all. Especially considering he was in office for some of the most stressful periods of Soviet history.