To understand a program, you must become both the machine and the program.
Any noun can be verbed.
Adapting old programs to fit new machines usually means adapting new machines to behave like old ones.
You think you KNOW when you learn, are more sure when you can write, even more when you can teach, but certain when you can program.
One can't proceed from the informal to the formal by formal means.
It goes against the grain of modern education to teach children to program. What fun is there in making plans, acquiring discipline in organizing thoughts, devoting attention to detail and learning to be self-critical?