Japanese artist, author, and illustrator Jaluka Nohana came up with a great life hack that will be very useful after the pages of your book got wet. It is quite simple really. Take a look.
If your notebook has gotten wet then just follow these simple instructions
Place a piece of white toilet paper in-between each of the wet pages
Put something heavy (like a stack of books) on top
Keep replacing the toilet paper until it soaks up all the water, and voila! Your soggy notebook is fixed