I define my days by how much I get done.  I judge myself by how much was accomplished on my list. I define my life by how many things I can complete.
On a day that I feel scattered and I don’t get much finished, I don’t feel very good about myself.  When I get calls it breaks my concentration and I feel pulled in too many directions. 
I’ve started to ask myself, “What do I need to do today to feel good about myself?”  If I can accomplish that very small list of one or two items, no matter what else does or doesn’t get done, I feel like I’ve had a productive day.  Sometimes, these are things I’d rather put off doing. And doing those things is a great accomplishment indeed!