I'd say it was an unintentional lesson in the merits of grit. When I went back to school my attitude towards my non-computer science courses did not change -- I still very much disliked them. However what did change was that I decided I was going to graduate no matter what. It didn't matter how I felt or how much I'd rather do something else, I was going to study and graduate.

And I did. And it was hard as hell. But I graduated and for the first time I really felt a sense of personal accomplishment. I hadn't finished college because someone told me I was supposed to, I did it because I wanted to.

Once I left college and I got to work full-time in my field of choice this lesson paid dividends. When I have a problem I really enjoy trying to solve, the hours can melt away. When I have a problem I really don't want to solve, I can still sit down and force my way through it. And don't get me wrong, my brain still fights against me in those moments ("Hey guy, go check Hacker News or Reddit!"). But most of the time I am able to recognize when it is happening and reign it in as necessary.

As someone who also had a longish path to learning to work hard, the answer for me was simple: practice.

Gains in focus time (for me, anyway) are incremental, so it’s not like you wake up one day and can focus for 12 hours straight. Accept that it will be a slow road, and just keep trying to stay focused longer, whenever you sit down to work.

When I see people comment that they can only focus on code for a few hours, I feel like a freak. I can focus on any one thing for 16 hours per day, indefinitely. I don’t know why. I don’t use tricks. And it energizes me. I have very low social needs. I doubt I’m neurotypical. I doubt John Carmack is.