Positive

Funny thing, the word positive has multiple meanings:
constructive, optimistic, or confident - for example, “I am feeling positive about my life today!”
consisting in or characterised by the presence rather than the absence of distinguishing features - for example: “You are HIV positive”
with no possibility of doubt; definite - for example: ““I am positive you will get that job!”
But also...
(of a quantity) greater than zero.
(of a photographic image) showing lights and shades or colours true to the original.
containing, producing, or denoting an electric charge opposite to that carried by electrons.
And, surprisingly…
dealing only with matters of fact and experience; not speculative or theoretical.

...So positive means many things, but in our daily use there are two that are potentially a contradiction: positive means happy, optimistic, confident... But also certain. It has to be done. The paradigm of “putting on a happy face”, or perhaps “fake it till you make it”, but DEFINITELY that is what you have to do. To win.

Language is a manifestation of how we think and make sense of the world collectively as a society.

“Stay positive, and you will win” could translate as “Never have doubts, do what you are told, don’t question the status quo, and society will reward you."