A few days ago a question was posted about side projects and how long it took for them to make money (and then the question of how much). It got me thinking, what was the "lightbulb" moment where suddenly you realized what you wanted to focus your career on, or the epiphany that completely changed how you work?
I think Lean Startup & Customer Development transformed the way I looked at everything I did as a software engineer. It reignited my inner-entrepreneur as well. Now I'm a data scientist and I work in Finance and I help get others in my company to have that same epiphany.