I hear that old people have a hard time accepting that they are old. That society will pass them and all they treasure by as quaint and out of style. Basically next to worthless in modern society. Its why older people always seem bitter. They finally realize where they stand in the grand scheme of things.
Not sure where you heard that, but as an old guy with a lot of old friends I'd say its wrong for most of us. Think about it. We're financially well off (a lifetime of earning), free of the responsibilities of parenthood (being a grandparent is far easier) and career, still have fairly good health (enough to go on a hiking or canoe trip, or bicycle tours in Europe) and being retired have the time, money, and good enough health to travel (well until covid, but I don't think the old were the hardest hit by that in terms of happiness, I'm far sadder at some of the things my grandchildren have had to miss out on because of covid than how its effected me).
There are studies out there saying the same thing, most people end up happier in their early old-age. I think late middle-age (all the responsibilities of family and career and very little free time), and extreme old age (ie over 85 when the body starts to completely break down) may well be unhappy times, but being just retired is great.
The worthless part is curious. Old people tend to have more money than younger people, and in our society, for good or for bad, worth is largely measured in dollars. In the grand scheme of things everyone dies. The sun will go nova in 5 billion years, in 10 trillion years the last stars will go out. Knowing that, its nice to get out of the rat race and just sit and relax.
Of course, there are some old people who are bitter. My observation is that they're same ones who were always angry when younger. Its a lousy way to spend a life.
On the other hand, very few old people watch MMA. None of my friends do, its all boxing and the regular team sports like hockey, football etc. I don't know any old people who care about the UFC>