Sometimes my notes to myself are less obvious. This morning, I read something like, "'You've seen how Inkeri gets,' said Robert. Edward nodded." Oh. He has? I guess he'd better see how Inkeri gets by that point in the book, then!
The people who talk about doing all the research before they start baffle me. This morning I verified that disposable razors were in wide enough use in the UK in 1950 that it wouldn't be anachronistic to a charcter to have had them (and run out). Maybe you can plan that kind of thing in advance. If I tried, I'd have reams of notes on what kind of toothpaste was most common among Brits that year and whether pointy or rounded collars were popular on young girls' blouses in Helsinki. Not that I don't have notes that will never get used. I know, for example, when and why Coca-Cola first got to Finland in any really popular quantities. But there's no such thing as "everything you need to know" for a book; or rather, there is, but I can't see any way you'll know what it is without writing and rewriting and rewriting the silly thing.
I'm waffling between thinking "I should get this done and out to first-readers by Easter" and thinking "I should get this done and out to first-readers when it's done and not worry about whether it's before or after Easter." Hmm.