No.2...optimism? pessimism?

I've thought (or perhaps i should say believed) that optimism was the way to go, or to put in other words, 'the key to success'; because if you're not optimistic about things, how are you supposed to find a way to move forward? The funny thing about this is that a) so far i haven't accomplished much i consider 'awesome' in my short life till now and b) i still have 'bad days' despite trying to go along with "always look on the bright side of life~". It might be so slow of me to realise (but at least not late) that being optimistic seems to have to go hand in hand with being pessimistic, and that whatever 'success' may be for a person, it seems to derive from happiness (the reason why i think the two go hand in hand is because being optimistic all the time is the same as pretending that there are no negative feelings inside yourself, and it's inevitable that we have them so i doubt that suppressing those feelings will get you far). Now i think 'happiness' is undefinable in the sense that people find it in so many different things whether it be reading to eating to playing video games to squishing ants. But for me, i think that whatever it is, it's from being grateful, though i guess i don't mentally say 'thank you' to each and everything that i appreciate; it's more of a subconscious act of my mind, and the build up of these small things is what makes me think 'hey, i'm happy right now'. But overall, that's the thought i've gotten to today, to be (even if subconsciously most of the time) grateful. 

This is me trying to figure out the thoughts that clump up my brain.