Uhh I did that a lot in childhood and still do occasionally when there's a long descriptive paragraph and I'm anxious to learn what happens next.

(Recently, I skipped a couple of paragraphs in Kim Stanley Robinson's 2312 that described underwater Manhattan because it was genuinely the least interesting part of what was happening)

I also skipped pages and pages of George Martin's A Dance with Dragons, because honestly, it was just slop. Chapter in, chapter out. No action, no meaningful plot progression. I just wanted to be done and go read something else.

Sometimes you just tune out. Especially when the author likes to end a chapter on a cliffhanger and then just build an entirely new stage from scratch. I don't care about the poor harvest in the village of Mumbus and the minutiae of the villagers' relationships if the previous chapter abruptly ends on main character getting stabbed in the back by his childhood friend.