Yes but if you work full time and you have a family this 2 hours per day become rare. It's also important to notice that your body require to have some relaxing time which is also needed to be in consideration. Yes you may remove all "wasted time" of your day, but at the end, your brain will need rest. Spending your whole life optimizing this time will just get you more chance to get a burnout. 18 hours per week on free time is huge and hard to get once you have children, friends, and social activities.
That's exactly right. As you get older, you begin to derive joy from things other than mastering new skills. I understand the OP's original post was more about time in the abstract, but the point you make is in fact the reality.
