I am not native English speaker but in my native language (French) and local language (German) the expression about seeing the glass 'half full' or 'half empty' also exists. I then also noticed that the expressions exists in almost every languages.
Does anyone know a bit of history of this expression? I am mostly interested in the origins, how it spread, and by what famous occasion was it is used.
the Wikipedia page is not very rich of such information, neither is Google.