It's a challenging habit to start but not as difficult as you'd imagine to maintain. That said, I've met a number of other professionals that sustain similar schedules. I have an array of hobbies including flying, rock climbing, tennis, and traveling. I've never been diagnosed with any behavior or personality disorder and organize social time primarily around the weekends. I also hit the gym every day which helps a lot. I completely credit any success I've had to working out frequently.

I don't cast any judgement over developers not choosing to reinvest. I also think it's critical to know your limits and stay within them. I've been burned out several times throughout my career and know where my limits are.

I am however very certain that this industry rewards continued learning and with the right mindset it's very rewarding both in the short and long term.

>It's a challenging habit to start but not as difficult as you'd imagine to maintain.

The question is, why would you want to? I don't spend any time at all staying current on my own time. I stay current on my employer's time. That's part of what they pay me for. If they don't want to pay for it, then I'm finding a new employer.

Furthermore, I just have no idea where you come up with 20 hours per week. The kind of software I write just doesn't change anywhere near that fast, and I'm doing cutting-edge R&D! When I need to learn a new thing to do my job effectively, I go do research and learn whatever I need to. I don't, and see absolutely no reason to actively seek out new things to learn that I have no immediate plan to actually use.

>That said, I've met a number of other professionals that sustain similar schedules.

Have you really? I've worked for years, and I'm not sure I've met anyone fitting this description.