Mouse worked hard during those months while Gundam recovered to be up to the responsibility that had fallen into his arms, he was still a child who would soon turn 11. In addition to all that, there was a certain disconnect in Mouse with the reality of the life that surrounded him.
A poop cleaner from a mining station lost in the universe would normally spend his entire childhood, his entire adolescence and part of his youth living in misery, with poorly paid jobs, poorly fed, worse housing, and suffering social exclusion reserved for those who could afford to eat just a meal that wasn't a grey puree made from organic waste.