Bet that led to an "Oh [insert Japanese word for 'shit']" moment when they found out otherwise.
Or as Bill Cosby put it, "First you say it, then you do it."
Maybe so, but who knows for sure? Yamamoto might have said that even before Pearl Harbor. I think he was pretty hesitant to do it.
They believed their own propaganda about Americans- that we had no honor and were cowards. Turns out, the American soldier, sailor, and Marine had more courage and honor than the Japanese. True, we had industrial capacity and might, but it didn't mean diddly squat when the Americans were fighting the Japanese at Guadalcanal (where the Japanese had more men, materiel, and better supply lines).
Unfortunately, we believed our propaganda about the Japanese- that they were pidgeon-toed midgets with bad eyesight...however, after Pearl Harbor, we adjusted.