Some of them probably date back ten years. I had scores, if not hundreds of the damned things. I knew a lot of them were probably broken, but going through and finding which ones were still was an impossible task. I sort my bookmarks by folders, and the stuff I check regularly was all in neatly-labled folders at the top of my list (kept there with "AAA" prefixes: "AAA Blogs", "AAA Comics", "AAA News", et cetera).
The older folders, I didn't check so often. In fact, I'd say I hadn't touched the bulk of them in two or three years.
Today, I realized that it was generally faster and easier to Google on any given topic than to hunt through my bookmarks, even if the Google search took me to a page that was somewhere in that long list. In fact, my first reflex upon thinking "I remember seeing a page that..." is to Google.
Given the speed of my connection and the convenience of the Search Toolbar in Firefox, that huge collection of links was just plain defunct.
So why keep'em?
Ahhh, if only it were so easy to part with physical clutter that way.