Why settle?

I have a client and friend of mine (actually she is the one who calls me her hairapist) and she requested a post on this subject of settling.  The request was weeks ago.  And, I have been thinking about it ever since.  Now please do not get this confused with my last post about expectations.  This isn't about the expectations we have of others or the stress we put on ourselves in our day to day life.  It's about what makes us happy.  And, why is that so many of us settle for less in life than what we really want?
This client I am referring to is a really intelligent woman.  She works hard at her job and she is feisty.  I love our conversations and I always take something away from them.  And one of the main topics of conversation is why she settles for a job she HATES.  Now, I am not sure if it is the work she hates or the company, but does it really matter?  Does it seem fulfilling to get up every morning with a feeling of dread about what lies ahead working for someone you can't stand?  What if it isn't your job?  What if it's other circumstances in your life?  Your weight?  Your relationship?  Your lack of motivation?  Why, why, why do we settle?!
I think one of the first answers is the fear of change.  Going outside of our comfort zone can be terrifying.  We get caught up in an internal game of "what if" instead of trusting out instincts or possibly even just taking a risk.  We think of all the things we have to "lose" if we take a leap of faith.
Another reason could be we get stuck.  There are periods of time where we get complacent for no other reason than a comfortable routine starts and before we know it, we have been in that same routine for weeks...months...years.  Yikes.  But isn't this life about growing and bettering ourselves?
I saw an interesting quote today.  I don't remember the exact wording but it was something like "does today look like something you would want written in the book of your life?"  I immediately thought of my unwashed and hair and makeupless face.  (So vain).  Then I thought about the time I spent with my baby.  The clean house.  The meal I was preparing for dinner.  And, the person I got to help with just a little bit of advice and some food to take home with him.  Every day isn't perfect.  But, I am right where I want to be today.  And, I am dreaming big.  And, you have my word I will make those dreams come true.
So in what part of your life are you settling?  And, what are you going to do to change it?  It's in your power to change those things you aren't happy with.  Don't settle for anything less.  And believe.