I read Ada Palmer’s Too Like the Lightning four times before it was even published.
It’s quite a common experience when you’re a teenager to read a book that blows you away, that causes the top of your head to come off and your brain to rearrange itself and be a better more interesting brain thereafter. I’ve talked about this a lot, both in posts here and also fictionally in Among Others, it’s one of the fundamental experiences of the SF reading kid. It’s a much less common experience when you’re grown up. I read books now and I think “Oh I like this! This is a really great example of that thing”. I may get immersed in a book and hyperventilate but I won’t finish a book and think “Wait, who am I? Why is the world like this? Do I even have a head?” This did that to me, it gave me that experience of reading SF when SF was new to me, the feeling that I am a different and better person because I read this, and not only that but a better and more ambitious writer.