1)To realize that what is done ,happened is enough.
ie he figures out that he has banged the head to the same wall for such a long time and now its enough.This circumstances result in most cases such as continuous failure ,continuous same scores etc
2)Ennui:
This is basically slow feel fo despair .This process is rather the slow and continuous tat makes the person to realize and he/she tends to change.The slow despair called ennui and boredom lends hand towards change.
3)Sudden realization that he/she even can do something:
In fact there are so many things that human tend to realize over the period of time.Over the period of time he/she realizes that even he can do that he/she has not figured out sometime.This realization leans him to different path and variably different world and thus finds him at the other end of road and changed Tweet