The rarest skill that everyone should possess!

Hard to find on the landscape - but in my view, one of the most important skills that anyone should posses. Tt costs nothing, but takes effort to acquire. I try to teach all of my students this skill. This ability is one of the most important things I have given to my son Felix. My father taught me … and I am very, very grateful of that fact. So what skill is it? It is as rare as rocking horse shite! It is that rare and wonderful thing known as CRITICAL THINKING.