- The paper suggests a theoretical game framework to explain collective action dynamics by learning processes. When a certain fact becomes common knowledge due to a certain event, people accumulate knowledge about the state of the world and act accordingly. We concentrate on a conceptual example of the bandwagon dynamic showing the insights which this approach adds to existing studies. We analyze two other conceptual examples showing that the accumulation of information does not always bring people to know the truth about the state of the world. On the other hand, it may make them aware of their ignorance. Several practical implications follow.