The addition of interest to the principal sum, enabling you to make interest on your previous interest.  For math and financial nerds this is a big deal.  It is how thousands of dollars become millions if invested for long periods of time.

Recovery is sort of the same way.  Your investment may not always produce linear gains (i.e. each day will not be better than the day before), but over time you do experience growth and healing.  

This is especially true with incorporating fear foods.  Initially it is really scary, but as you expose yourself to these foods and see that you are able to handle them, it gets easier over time.  And when you've done enough fear food exposures, the foods you used to be afraid of simply aren't scary any more.  Eventually all food becomes neutralized.  

In what ways can you invest in your recovery today?