Idk what the appropriate saying is, but a lazy genius will often find the best & quickest way to solve things/do their work just to relax the rest of the time. Our MC seems to be one, as he showed the barest minimum just to get by but he survived anyway. He's not where he is for being truly mediocre or lucky. & some people that know him still only see him for his personal interests rather than his achievements, which is kind of shallow of them if you think about it.
Lol I like that shaking hands to them is a ceremony of betrothal. I had the same idea in my own writing that shaking hands are considered a serious marriage proposal so if the other party takes the hand it's considered official too, no matter the gender XD