You know that friend or acquaintance who has put up with so much in life but is just so hardworking and positive and happy? That one who lost a parent at a young age, or just had a really bad home life, or had health problems but it doesn’t really seem to affect them emotionally and they’re still so kind?
I think Lance is one of those people.
People talk a lot about his humor being an “act”, or a front for his insecurities. But maybe it comes from years of needing to be positive in spite of some really bad circumstances? Maybe he lost a parent and had to step up into that role for his younger siblings. Maybe someone in his family was dealing with a life-threatening illness. Maybe things were just really tough financially.
We know Lance has a big family (he was thinking of them in the scene where all the paladins were mediating and clearing their minds of whatever else they were thinking). And Keith grew up with no family at all. Maybe this could be a source of tension later. Keith thinking Lance has no right to feel sorry for himself because he had a huge family to support and take care of him, not realizing how much of it was also Lance taking care of and supporting his family.