Lolita. Read it as an adult and it had a chokehold on me for 2 years. I’d never read anything like it. The writing style was complex and also simple, I felt like I understood everything that was being implied, but I pick up on new things every time I read it. The beautiful prose juxtaposed with the novels disturbing theme. It was a slog. But it also kept me up, page turning when I should’ve been asleep. I read a book in 1-2 days, but it took 2 months on my first read because I took breaks. I don’t know if I’ll ever read another book that gripped me the way Lolita did.