My co-worker calls me "Koala Mom" because I was joking around about how I don't sign my daughter up for activities because I'm too lazy to drive her. I'm exaggerating of course. We do sign up for an interesting course if it works for our schedule and if we think it's worth it. But, not that much. We have a lot of down time. I mean a lot. Enough of it that there are moments in our day where we look at each other like castaways on an island. "We're still here? What do we do now?"
There's a reason why I like to have lots of time to do "nothing," which basically means we have nothing planned. I want to get bored. I want my daughter to get bored. Because boredom leads to creative ways to fill the time. Sometimes destructive, sometimes constructive. All of it leads to new experiences and discoveries that might not have been considered before. It means time to do a lot of thinking. Which can sometimes lead to dark places that the mind doesn't want to consider but, I know from experience that travelling through that dark tunnel often leads to some revelation about yourself or the world. The thing to remember is that it is a tunnel, not a pit.
I also recognize that we live in an environment where being bored can be a luxury. It definitely feels guilty to have so much free time. But, I made my life this way. It's a choice and I think that if you are complaining about not having enough down time than you should work towards creating a life that allows you to make those choices as well. Fill your time like it is a tiny, tiny box. Fill it with things that give you joy, arouse your curiousity and always leave room for something new.