Flaps overrated?
Not relevant to current passenger jets, but if you read the book "Thirty Seconds over Tokyo" by Ted Lawson (who was a pilot on the Doolittle raid of WWII) he forgot to set the flaps of his B-25 while taking off from the Hornet. Only realized it when he put his hand down after takeoff to raise the flaps.
Pretty amazing that you had a medium bomber that was both very heavily loaded and never designed to take off from a carrier (no catapults in those days), that was still able to get into the air without flaps.