Agreed, the same goes for reference books. In a paper book, I'll often find things that I didn't realise were important at the time, or a later conversation wi

Agreed, the same goes for reference books. In a paper book, I'll often find things that I didn't realise were important at the time, or a later conversation will bring to mind, and I'll recall something fuzzy like: "It was in the lower half of the right-hand page, a few pages after that diagram with the donkey in it", but can't recall anything that will allow hard searches.