True story from a part of my life from around the time the author mentions: A Fields Medal winner (this is the highest prize in the field of mathematics, for solving hard open problems that puzzled people for centuries) I have known, by himself read the source of Unix (Sun OS) and learned C. He did it when a young PhD student presented him with code related to problems he discussed with this teacher.
This being said, my 9 year old surprised me this week when he showed me an online computer game that someone abandoned which he fixed by going into the code. A few thousands had played it and given it 4 or 5 stars by the time I saw this working. I had no clue that a kid could do something like this in a rather fancy 3D game. I'd say, lets leave the kids to themselves and try our best to help them keep out of trouble as they go along.