A world that derides weakness, a world that has no place for the weak and no care for the useless.
Even the beggars were only given the right to begin a city if they have given a big part of their life to the city, otherwise, they would be thrown out to the jungle to fend for themselves.
This was a culture that had been in place to secure resources and even if the lack of resources is not a problem anymore, it doesn't mean the habits that had been cultivated would change so fast.
It was for this reason that Alfin feared showing his emotions to others and the one time he didn't, he was forced to suffer multiple times due to it.
Weakness is sin, whether it is a physical weakness or a mental one. And Alfin understood that he might be physically strong, but his mind was unstable and fearful of the future.
It's why he started to find different bizarre things to be happy about, like pranking his brother, spreading the words of the aliens, and other similar things.