"This simple phrase, "follow your passion," turns out to be surprisingly pernicious...The verb "follow" implies that you start by identifying a passion and then match this preexisting calling to a job. Because the passion precedes the job, it stands to reason that you should love your work from the very first day. It's this final implication that causes damage. When I studied people who love what they do for a living, I found that in most cases their passion developed slowly, often over unexpected and complicated paths." Cal Newport shares more in this thought-provoking article.
