Lol... is this a trick question? If society is garbage then I doubt if a person could be truly happy.
Its a matter of perception - but human perception is unstable.
Self awareness leads to a perspective bias by the thinker that assumes all his feelings, ideas, memories and personality traits are his own and that there is a solid and static foundation for them. This really doesn't seem to be the case at all. The chemical balance in your brain at any given point changes not only your perception and interpretation of new input but also how old data is reinterpreted as its being recalled. As an experiment you can force yourself into a chemically induced depression through massive sleep deprivation and then try to recall recent positive experiences. The mind will latch onto even the most minor negative aspects of the experience and massively inflate their significance. The entire emotional context surrounding the experience will change and the memory will have permanently mutated. When you recall the same experience later in a normal state of mind the emotional aspect becomes ambiguous.
Humans normally don't internalize any problems outside of their small social sphere - all the problems come from within. If you have 1-5 dogs you'd probably name each one of them and become emotionally attached to them. If you have 50-100 dogs in your back yard it just becomes "those god damn fucking dogs in the back yard". There are soft limits (which varies among different types of primates) on the number of entities that you can form meaningful bonds with.
A human's social sphere tends to be very limited in scope. If you have people within it that aren't garbage there is no real reason to _emotionally_ care if the rest of humanity is fucking retarded. You may care out of principle or based on some logical argument but that type of shit does not lead to a huge emotional response in itself - although it does have an impact to a certain extent.
Life (and society as extension) can arbitrarily feel great or like a living nightmare based off the composition of some goo sloshing around your brain. Experiencing these types of loose shifts in perception leads to a type of emotional detachment from them that facilitates clearer thinking - not only should you question what other people tell you but what your own mind is telling itself.
Its all too easy to assume the sky is falling when in reality its you who is dysfunctional. On the flip side: people who are naturally always carefree/happy tend to be completely oblivious to potential problems.