Sunk costs, body image, and rationality

This week I'm reading a book on Rational decision making that claims that sunk costs should not be considered when deciding where to go from here.  By sunk costs, they mean time, energy, and/or money already expended prior to the current decision.  For example, suppose you have already paid for a weekend vacation.  Once you get to your destination, you get sick and realize that you would probably enjoy driving home and curling up in your own bed better than staying in the hotel bed.  In such a case, it would make sense to ignore the cost already spent and go home.  The sunk costs of the vacation should be ignored because staying at the hotel will only make you more miserable.  The sunk cost provides an opportunity, but that does not mean you should take that opportunity.  The rational question is "What should I do now?"

This past week, I read a similar idea in a Facebook discussion on body image.  Someone made a comment (I can't remember the specific comment that inspire my post, but it started with Kelly Elmore) that you should not set the standard for your body image based on where you may have been in high school or college, but accept where you are at now in order to move forward.  Anything less destroys your self-esteem.  Accept your body in its current form and condition.  Recognize the value that your current body brings to you.  While there may be room for improvement to bring more value, people should not conceive of their current body as a dis-value or as a negative.  Doing so is a common mistake, but a mistake non-the-less.

The similarity - the past is in the past.  While it might not seem appropriate to consider body image in terms of sunk costs, an alternative might be to think of it in terms of sunk opportunities.  Opportunities missed, passed up, and regretted.  Things we could of or should of done the last 5 years so that we would not regret the place we are in today.  Certainly, regret can inflict our conscious (that's not a bad thing), but it should not consume our conscious.  We should use regret as motivation to change, not as a reason to avoid change.  We should use the regret to identify what is of value, so that we may act to gain and/or keep it.  That is the rational thing to do and the rational way to act.

While we have a body we have inherited from our past, we are not controlled by our past decisions.  There may be limitations on time, capabilities, energy, and opportunities.  But we can change the hierarchy of our values and shift around priorities if need be.  The key take away - discover your hierarchy of values and act accordingly.  And above all, don't let your past stand in your way. 

Now that's thinking rationally :)

As a disclaimer - I found the books' discussion of rationality too pragmatic in nature.  Hopefully, I'll get a chance to write more about that later.