Certainly, you went through many posts that treated the same subject but here in mine, I am going to do something different.
I will tell you my story, it truly manifests how managing time can be hard sometimes, and feel disappointed other times.
First of all, I didn't care much about my time until I reached 19 years old. I already got my baccalaureate and moved away from my home to study at university.
It wasn't easy but I understood that I had to manage my life and so my time. I started spending my journey more wisely but did not kind of focus on important things. My day went like studying, reading, playing memory games, listening to positive podcasts, preparing my meals, and spending some time with my roommates.
You can see that I was doing pretty good but I wasn't actually: I didn't have priorities, I only focused on absorbing the positive energy, and improving my memory skills more than anything else including my studies.
In his book "So Good They Can't Ignore You" Cal Newport argues that you should know what's important to you, the things that can change your life such as your work, improve your writing skills, and reading (these ones are my priorities). They can be defined differently from one another, you can ask yourself: what are three things to be done when I only have one day left in my whole life? I think you already found the answer.
The second thing, plan your day before. It's so much easier when you have a fixed schedule, you know your free time, and it's obvious when you will finish work, and how much time you need to get stuff done but in the case of flexible hours, it's tricky to manage your time: you have no idea when can you get off your work, you're often confused so what do I have to do?. I personally think that you should schedule your journeys anyway because when you do, you prevent yourself from wasting time and being chased by distractions, at least you're aware of the things that have to be executed in the day and how much time you have to spend on it even not knowing the exact when and it's not bad to adjust your planning whenever you need to.
We live in a world full of distractions, and it seems really hard to take control of them. There's no way to do that other than having a cause and a motivation for a better life. If you're not aware of the importance of the time you're wasting on social media instead of expanding your intellectual and social skills, nothing is going to change. It took many years to decrease the amount I spent on social media but it's still important and I'm still struggling.