After the Quirkless Izuku Midoriya meets All Might, he becomes the successor to All Might's Quirk, One For All, which means he must eventually go up against All For One and Tomura Shigaraki.
These guys are able to smile thoughtlessly 
because All Might is smiling thoughtlessly.
.هؤلاء الناس يبتسمون ببلاهة لأنّ أولمايت يبتسم ببلاهة
Esta gente sonríe como si nada
Esta gente sonríe como si nada
Eux aussi, cette insouciance…
Questi qui continuano a ridere 
come se nulla fosse
Essa gente consegue sorrir assim
porque o All Might sorri assim.
Эти люди могут так бездумно улыбаться,
потому что Всемогущий бездумно улыбается.