Thing a lot of people forget is that he's the most traumatized one on board too except for maybe Seven of Nine. Having to abandon his homeworld because a weapon was used on it that coated it in fire. Then when he went back as part of a military rescue team, he had to look for survivors in a place where their flesh was melted into the pavement. Lost not just his planet and family but a huge amount of his species. No family or anyone left and became a drifter scavenger that gnawed on the bones left over by Kazon and others.

The poor man's life is an utter tragedy but he keeps going.