Courage, self confidence, and willing to sacrifice is all that's needed for a revolution to start.
What is needed for a revolution is a significant portion of the populace to feel that they have nothing to loose. That has been the case throughout history. Seemingly autocratic regimes are tolerated as long as the percentage of population that feels this way is substantially smaller than those who feel altering status quo would cause them to loose something they have (aka middle-class in modern terminology). This is the buffer between the (lots of) haves and have nots.