On Monday, I had my first class and decided to open with a discussion about change. Often, I think how story is about characters managing change. They are responding to the world changing around them, or changes within themselves, or they are trying to create change in the world or themselves. They will continue to respond to this change until the situation returns to a period of stability.
If I go back to my high school physics, change would be measured by its displacement- an objects movement from point A to B shows change. To cause this change, force, which is the strength or energy exerted, is required to cause motion or change.
The calculation looks like this:
WORK = FORCE x MOVEMENT
To create change, either inside or out, requires work and effort.
Of course, story has a worse possibility where characters resist change and fight against instability by ignoring it. However, this non-action still requires work.
If a situation is changing around them, whether it is aliens are invading, a spouse is leaving, or the characters are growing older, they can either change with it, which sometimes requires less energy, or push back against it, which sometimes requires far more energy and work.
Indeed, if aliens are invading, maybe pushing back is the better choice. It will require a lot of energy, as well Will Smith, Jeff Goldblum, an alien spaceship, and an Apple computer.
However, if it is about growing old or past beliefs are proven wrong or the person that we've spent a lifetime with no longer loves us, then perhaps action must be taken whether it's wanted or not.
Unfortunately, in stories, as in life, the energy spent worrying about this action can sometimes be the biggest effort of all.