Thus article isn't very well written and you probably should consider skimming it if youbclick the link, but I think he still made an interesting point:

We've conflated "interesting" with "easy to consume."

He talks about how we are rarely at a loss for something to do -- our devices provide an unending firehouse of things to learn about, do, or be entertained by. However, that makes the momentary feeling of friction in learning all the more dangerous.

boredom isn't having nothing to do. I had plenty of material to go over. Instead, it's the friction of deep focus. It's the resistance you feel when you move from consuming information to building those neural connections in your brain.

Learning is hard -- at least until you get so absorbed that you don't notice you are learning. It takes some amount of persistence through what feels uninteresting or perhaps even not useful before things start to open up.

His solution is to set a timer for 25 minutes and refuse to move on until you've spent that amount of time on a thing. This seems like pretty good advice to me.