I retired because I had a knee injury, my cartilage was wearing out, it was painful and I couldn't put in the four hours of practice each day that I needed to. ↗
We had to depend on other institutions to do research on our behalf. We had to use the information that already existed to craft the best practices to distribute throughout the country. And we had to do all of that in ten months. ↗
I maintain that many an inventor, many a diplomat, many a financier is a sounder philosopher than all those who practice the dull craft of experimental psychology. ↗
If there's going to be an SAT, it's probably practical to invest in a book or perhaps in a course, but I'm sorry to say, I went to some classes that my kids took and it was clear in school that what they were doing was just SAT training. ↗
Defining OO as based on the use of class hierarchies and virtual functions is also practical in that it provides some guidance as to where OO is likely to be successful. ↗
It wasn't all spent on practicing, I did do other things! but the classical guitar means a lot to me so I spend many hours building good chops and getting a good program together. ↗