mark cubanThe traditional markers of success don't cut it. Mark Cuban pictured.Michael Buckner/Getty
When we talk about a "successful" person, we're typically talking about someone who's got billions in their bank account, someone who's authored multiple bestsellers, or maybe someone who's in charge of an entire nation.
But if you ask people who fit the conventional definition of a successful individual, many will tell you that those achievements aren't what make them feel accomplished.
Below, The 90 Day Shift has rounded up what some of the world's most powerful and impressive people — from President Barack Obama to the late author Maya Angelou — have to say about success.