What does the following quote mean? "Don't carry a grudge. While you're carrying the grudge the other guy's out dancing."

The point of this quote is that life is too short to spend
on anger.  There is no point in wasting your emotional strength on being angry. 
Instead, you should just be happy and let bad things sort of slide off your
back.

In this quote, the implication is that the person who
holds the grudge is the only one who ends up unhappy.  The other person does not really
care.  They are not worried about any grudge so they are able to be happy and "go
dancing."  The moral of the saying, then, is that it is better to be the person who lets
go of things and goes out and has fun.  This makes life more satisfying and less
stressful.