There were a few interesting things I've noticed by randomly viewing old bookmarks. The first is that linkrot is a very real thing and the web is decaying at a measurable rate. Second, it's amazing how limited my memory is. Half the time I don't remember something I bookmarked from years or even months ago at all. It's new to me, all over again. I'm going to bookmark this discussion and then completely forget it existed within a few months at most. Regularly reviewing old web pages and notes makes me feel like my mind is a sieve, as well as highlighting how my interest and thought processes have changed over the years.
I'm really interested in this topic, feel free to contact me to discuss.