Comparison... Good or Bad?

So you know the old saying that goes something like, "You should never compare yourself to anyone else?"  I'm always telling my kids something like this.  I was thinking about this today, possibly because it was right on the heels of my son getting his MSP test results.  You know, you might say this all the time, but really how will you know how well you do at anything if you don't compare and contrast yourself with others?  What becomes your measuring stick if you don't have any perspective?

My mother is in the hospital now, so she has been in my thoughts a lot this week.  I was thinking how extraordinary she really was when I was younger.  Although, at the time she was just my annoying mother who never let me do anything.  We fought so often I can hardly think of a time in high school when we weren't fighting.  That is beside the point.  It is not until I am the adult that I am today that I realize all the amazing things she did.  It is with my perspective and the person who I am today in comparison (and contrast) with my mother, that I really begin to appreciate the person that she once was.

In appreciation of my mother I have to say that sometimes comparison is a good thing.  What do you say?  (Because I would like to compare answers...)