When you realize you're in "good days" the feeling is called bittersweet. Therefore one should make the most, as soon as you realize the time is bittersweet. This helps prevent regrets of "not doing enough" later. Like today, it's not too late to make the most of your upcoming weekend.
I'm a time-traveller, and one of the things that sent me reeling was realizing just how unaffordable housing had become, and how bad inflation had gotten over time.
I went house shopping in 1995 as a curiosity and the realtor goes: "Well, we have a lovely three bedroom starter home available for $150,000".
My eyes almost bulged out of my head, because a monobloc one-bedroom "starter home" goes for almost $9 million in 2083.
If I could find out one thing about the future, I'd want to know if the GOP ever managed to accomplish their goal of turning the US into a fascist hellhole.
Rule of thumb: it will always get worse in some way, so you will always remember the past fondly, also because you usually tend to forget the bad parts.
I remember I was sad a lot in my childhood, and why. I still look back on it fondly, likely because now I know how the things that made me sad get better/solved in the future, and because my childhood was free of a problem I currently struggle with now.
And on a much shallower note, the pop music that got played everywhere all the time was music I actively enjoyed.