Barry at Enrevanche directs me to this great article at boxesandarrows, about web users' four modes when seeking information.

1. Known item

2. Exploratory information seeking

Those are the classic, obvious ones. These two newly defined modes resonate and inspire:

3. Don't know what you need to know

4. Re-finding

They apply to everything. "Don't know what you need to know" - still chuckling.