I personally try to have the outward appearance of being positive because I'm constantly fighting the dark place. Yes. Sometimes I like to sit in the dark place because it's easy and I hate fighting it all the time. But I won't be fake about happiness. I think there's a very good reason why I have resting bitch face most of the time. But I can and will smile if that's part of my job (working retail). And I am not a happy baker - though some people may believe I am. I bake because I get the pound the shit out of something...which makes EVERYBODY happy. LOL
So, while I do advocate positivity - it's never with a tank of helium up my ass either. ;)