>It's really that simple.
Almost.
With OUT (C+O2) humans can NOT breathe (sans machine). It is (C+O2) build up in lungs that causes humans to suck wind. No (C+O2) can NOT. Ever Yawn? or Lactic Acidosis? - extreme end of scale forcing you to BREATHE.
>A hundred years ago, EVERYONE knew too much nitrogen
Since Atom is approx 80% Nitrogen, anon suspects 100yrs ago they knew sh!t.