I had to come back to respond again because I'm watching Mother Night right now on account of this conversation. How do you like Mother Night and Shutter Island at the same time? Seems impossible to me.
But setting that aside, I wanted to say that if you haven't read the book, you should. The book and movie are both perfect, and serve to inform the other. I don't know of any book-movie combination that works so well. Surprised you've even seen the movie, as far as I can tell it's the greatest hidden gem in the history of cinema.
its been a long time since ive seen mother night, but i have seen it several times and it was good or even better each time. ive seen shutter island maybe twice, it was great the first time as the twist was really well foreshadowed but i didnt see it coming. the second time i just watched it to find easter eggs and foreshadowing of the twist. but ill prob never watch it again, it doesnt have that kind of quality to really keep watching it. i just thought it was a really good cast, and a really well written twist. i always laughed at the people who said "what really happened", it seems clear, he was insane and the plot is just as described.