A large delta aircraft like Concorde needs no flaps as the large wing
area traps a cushion of air beneath it and the ground during landing.
Also the characturistic nose high attitude of deltas on landing not
only provides hi lift but hi drag too. Perhaps when you was taking off
in that Concord you allowed the nose to rise too high. Beleive it or
not correct technique for take off in most deltas was to lift the nose
wheel only a few feet from the runway and the aircraft would rise on
attaining correct airspeed.