This is all part of growing up, I guess.
Let’s leave aside how the setup of Rin and then Kouki’s mom getting sick in the last two episodes of Usagi Drop was an excellent showcase of how good a couple Daikichi and Kouki’s mom make. True as that may be, it has nothing to do with why they helped one-another. They did so because they’re both good-natured, kind people who know how to take care of others, and who seize opportunities to help.
I was childish for seeing myself this way, but I haven’t thought of myself as a nice person. I’ve always had a bitter, calculating attitude about what I say to others when they’re in trouble. I’ve been withholding my sympathy or simply denying it to myself.