This made me smile at first -- but I realise there is a big cultural difference here.
It reminded me of a friend of mine, an American professor who was teaching in a theological college here in France. He was quite shocked at first because we French sounded sooo negative to him -- not in politics btw (he was rather critical of US policies himself) but in everyday, or especially academic, issues. IOW when it's bad we don't say it's "great".
Well, even among French I think I have a somewhat negative tendency. Not necessarily sad though -- I'm quite fond of pessimistic humour (e.g. Murphy's Law).
What I do find unbearable is mandatory positive thought (remember the WT "spiritual paradise" and the token smiles in assemblies). Repressed negativity can become really harmful. What "positive thinkers" ban from their conscience and speech others have to express, shamefully or pathologically.
This is not to say that we don't need to correct our thinking sometimes. But I feel the starting point is accepting the negative rather than repressing it. Just a French thought.