One can learn it from a book in about three weeks of hard work. A small disadvantage of HTML is that it only allows an approximation of the final look of the page. Different browser applications will interpret the same HTML file slightly differently. Marc later left Mosaic and started the rival Netscape Communications. Now the internet is very simple to use.
Many children are adept at net-usage.
In many cities, the public libraries are wired-up. I learned some of my first computer-knowledge from talking to homeless people at the San Francisco Public Library. As prices of computer hardware spiral exponentially down, there may come a time in a few years when everyone will be on-line. They retail for 600 dollars, and the price continues to drop. In three or four years, many homeless people may have computers on their shopping carts.