When I was a teenager, I spent my entire free time playing video games. Mostly League of Legends, but also Call of Duty, Age of Empires, or Minecraft. This wasn’t a casual hobby. It was an obsession. I would come home from school, toss my backpack into the corner, boot up my computer, and play — often late into the night. School was secondary.

As I got older and played fewer games, I felt more and more daft. Others had spent their teenage years going out, experiencing things, getting to know themselves, and building relationships. And then, there was me. I had spent my young years commanding cartoon figures in virtual worlds.

Adding it all up, I must’ve spent over ten thousand hours playing video games. Ten thousand hours — that amounts to 20 hours per week for ten years or, say, 40 hours per week for five years. Ten thousand hours is also the time it takes to master a skill (at least according to one controversial study). If I hadn’t played video games, I could’ve mastered the violin, written a book, or competed in professional bike races.

But I didn’t. And the toothpaste of time can’t be put back into its tube. So, ostensibly, those ten thousand hours were frittered, flushed down the drain, and downright wasted.

Right?

After the video games went, YouTube came. It was around this time that I discovered Casey Neistat — a YouTuber who used to upload daily videos while also running a business, a family, and marathons.

One particular video hit me like a domino block in the face. In that video, Casey talks about time management. He starts by quoting Seneca, says that time is his most valuable resource, and explains that he tries not to waste a single moment.

“The only time I really get bummed out or depressed,” Casey says, “is when I’m not being productive, is when I’m not accomplishing or doing or contributing in any way. Nothing makes me less happy than relaxation and sitting around with nothing to do.”

He then sketches out how he structures his day by dividing his time into six broad categories…