A small college philosophy professor, despairing that life has no purpose even though a female prof & an adoring student bed with him, finds meaning in murdering an allegedly evil man, thus improving the world.
It’s A Wonderful Life (1946)
When a small town banker thinks he has failed an angel shows that if he had not been born, the town would be worse off without him & his good deeds.
All Is Lost (2013)
When his yacht is rammed by a rogue cargo container in the Indian Ocean, the sole sailor fights for survival against overwhelming odds.