I saw a documentary once about the last days of Adolf Hitler in the bunker and his mistress / wife decided to have a dance with maybe 100 or so people and they were all determined to be happy and to be positive and optimistic and in fact a Russian bomb hit the bunker while the dance was going on and both Hitler and his wife would commit suicide shortly thereafter.
This was a powerful image to me ever after.
That human beings can literally ignore evil and ignore reality and just pretend to be happy and that is NOT something to admire.
I see the same thing with those motivational speakers and personal development gurus who teach about being happy and be proud and just tell your self that everything is wonderful - so yes anyone can do that, but it is living a lie and undermining their own life with nonsense.
There is an old and valuable and different message from the Buddha called the
first noble truth which is that the one reality of life is that we all have pain and sorrow and suffering, and that is an absolute truth, so we can act happy but that happiness is temporary and it is always covering up the hard realities of pain and sorrow. That is a part of the message of Jesus too in that Jesus said to take up our own cross - and not to toot our own trumpet.