As long as some Humanity exists we´ll always hear people complain for sure. It´s just normal for some to do it on a daily basis unfortunately...
But you are totally right, optimism is the best at all times. To think positive and enjoy your life, that´s as well my way of thinking since a long time. I´m glad you were able to achieve this significant change in your life 20 years ago :)
I had to learn at an early age haha ... It's odd when you seen your old friends from 20 years ago, and they are the same people now. smh lol
Some people change, some don't & we continue going our own way while keeping those in our lives we think are worth it.