“There is nothing either good or bad,but thinking makes it so.”—William Shakespeare, “Hamlet”
One of the greatest sources of unhappiness, in my experience, is the difficulty we have in accepting things as they are.
Without judgment, without wishing for otherwise.
When we see something we don't like, we wish it could be different — we cry out for something better. That may be human nature, or perhaps it's something that's ingrained in our culture.
The root of the unhappiness isn't necessarily that we want things to be different, however: it's that we decided we didn’t like it in the first place. We've judged it as bad, rather than saying, "It's not bad or good, it just is."