It’s extremely tempting to fill spare moments with activity: books, tasks, web browsing, chat. Culturally default behaviors fill spare time with others’ ideas; to make space for my own, I have to get comfortable with “empty” time. I find I often have to get bored before I can Get curious.
So the exhortation is: when you find yourself bored, stay with that feeling instead of immediately reaching for a book or other activity.