Tex said: "Now, why is it that pain and evil seem so real, while mirth, joy, and happiness do not? I think one reason is that we have not learned how to be happy... We attempt to use joy as a narcotic, to dull the pain, forget the hurt, and pretend that all is as it should be. Thus, when our merry-making comes to a close and we are sober once again, we find that the memories remain, the pain remains, and the narcotic of mirth had only a temporary (and not real) effect. After a while cynicism becomes our general response to the pain and evil, and this is viewed as progress and maturing from our childish attempts to escape the pain with desperate attempts at merriment."
Will anyone disagree with this statement? People who think that the world is good overall agree that there is some bad, some pain, some darkness in it; and people who believe the world is dreary over all agree that there are some islands of fleeting joy and mirth in it.
The question is not whether the glass is half full or half empty, but whether there are more full glasses than empty ones, with all of the empty ones having their place, so all is well or there are far more empty ones, and all of the full or seemingly full ones will be empty soon enough. In other words, it is a question of which of these two (good or bad, generally speaking) are on the "outside," are the widest context, or deepest foundation.
This view of sadness and soberness as ultimate maturity assumes, then, that "bad" (and darkness and pain and futility) is this widest context, this deepest foundation.
I hate to bring us back to epistemology, but a) which is a truer picture of the universe and b) how will we discover the answer to a)?
You said, "we have not learned to be happy." I ask, "Is it possible to learn to be happy, or not?"