The tenacity or persistence to continually perform/do/say dumb things. Repeatedly performing, what most intelligent people would consider dumb acts or narrative. To always 'shoot yourself in the
foot,' self-sabotage; saying something which obviously stretches the
truth to fit one's narrative (usually stupid.) '
foot in the mouth' gossip or speaking
ill of someone standing right behind you. Repeatedly trying to change an outcome and getting the same results is an act of dumbacity.
I can't believe the dumbacity of some people. They go out all the
time badgering others in futile attempts for a
different conclusion. It's over, get over it, what dumbacity! He, who shall not be named, repeatedly promulgates a negative narrative on a the LOSS he cannot understand and claims 'stolen' from him. The dumbacity of the people which believe him.