Falling.

Uncertain.
People always sing about last chances;

Imagine your life backwards, knowing all the most important moments that would happen to you. This will be the last time you have lunch as a class together, or the last time you get to see someone who's of a significant importance to you, or the last time you kiss your grandma goodbye. Your last chance to tell her you love her. If you knew every moment was going to be significant, wouldn't you try to change things while you still had the time?