I don't know all the specifics but it sounds like they got a whole load of stuff from OBL's compound. They said among the items was his journal. He was far from retired and was still thinking of ways to attack.
TIS
"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK
