The baffling part is that Morbius refuses to call his friend by his name: he calls him "Milo" instead because his bed used to belong to a dead kid of that name, so Morbius decides Lucien is gonna be the new Milo until he dies too and they bring in another one. That sounds like something a kid would do because kids are buttholes ... but then it turns out the doctors are also calling Lucien "Milo," for some reason? Like, even in life or death situations. They know his real name (they introduced him to Morbius!), and presumably, they remember the original Milo, but apparently, they too decided they're just not gonna bother learning kids' names because they die so often.
Cut to 25 years later: Lucien is now a millionaire, and everyone calls him Milo. We honestly assumed the movie had forgotten that wasn't his real name until the very end when it's uttered again for the first time in almost two hours. At what point did he give up and accept he was gonna use the name of a dead child he never met for the rest of his life? How did his family feel about it? Give us that movie, Sony.