The way I see it you also learned it somewhere sometime ago. Coursera offers more and more courses some of which are quite in-depth. Motivated person may be cap

The way I see it you also learned it somewhere sometime ago. Coursera offers more and more courses some of which are quite in-depth. Motivated person may be capable to finish university degree in couple years. Coupled with the fact that this person may be gainfully employed in similar area, it will not be that hard to imagine him or her to eventually switch to a position that requires all the old and new knowledge. IMHO, examples that were given in the original article are in line with what I described.