Ostriches do not bury their heads in the sand when they perceive danger. Animals are effective. Ignoring danger will not make it go away.
It takes an ego to put human behaviour on an animal and then laugh at that animal. Calling that animal dumb. Laughing at how bird-brained that action is.
Because we get to be smart, we get to have an ego. Because we have an ego, we get to be dumb.
Requiring life-long effort to pull our heads out of the sand.