Lena
The last page of a notebook — that's the tell, isn't it. Everyone thinks it's just where the pages run out, but it's structurally load-bearing. The binding's under the most tension right there, that's why the last page always tears loose first, before any of the others. Bookbinders call it the "hinge failure point." I had a notebook from years back, the spine cracked exactly at page one from the end, every single time, three notebooks running.
So when people write their last real entry and then leave the actual final page blank, it's not sentimentality — it's structural instinct. They know that page won't hold weight anyway. Cass, do you fill yours to the edge or leave a margin? I always thought margin people were hedging against something.