I didn't say it was false. I said that you are changing your perception of the water unless proven otherwise to some extent.
Falsification would come about by testing the chemical makeup of each glass of water.
An object isn't real until its actuality has be perceived.
Reality is the internal construct created by our interpretation of the actuality of an event, environment, or object.
And don't worry, cheerfulness is not a problem. It cheers me being right all of the time.