It's not okay to not finish what you start.
Jim is exhausted from working on a labor intensive project all day.
Jim wants to go to bed to rest his body.
Jim chooses to get some rest and start again fresh in the morning.
Jim decides to quit on the project due to how much labor it requires and turns in for the night.
Jim is well rested and has more energy to complete the project.
Jim feels regret for spending so much time on the project in vain.