In our parent's generation, people first learned a profession and then devoted the remainer of their career pursuing that trade. The skills acquired during college, trade school, or apprenticeship were sufficient to endure through 30 years or more of productive work.

The globalization of the Internet, along with the rapid pace of technology evolution, lead to a world where professionals must constantly renew their skills in order to remain competitive. Just as the farmer replaced the axe components, today's worker frequently replaces skills even when continuing within the same profession.