I'm not neccessarily sure of this analogy but I want web browsing to be like a book. I "open" a web page and it's there in it's entirety. Waiting and ready for

I'm not neccessarily sure of this analogy but I want web browsing to be like a book. I "open" a web page and it's there in it's entirety. Waiting and ready for wherever I want my eyeballs to go. I'm not averse to javascript or to images(my site is almost all images) but the slowness of so many sites these days says the high broadband and cpus can't keep up. And maybe someone can explain this to me but why does going back in the browser seem slower or more intensive than loading a new page? Is that because the broswer itself is trying to load the previous state?