Do you ever talk to people that leave you feeling like you are completely drained afterwards?  Perhaps you have some of those in your life that only speak to you when they need a favor.  As you proceed in your life's journey at some point there comes a time when you have to set some boundaries with respect to those individuals.  You want to have an inner circle of people that support you and continue to add value to you.  Some people are also better than others at saying the word no.  Saying no does not mean you have to justify why you say it, you just do.  I believe that we get hung up sometimes on justifying saying the word no.  Saying no does not have to be done with a harsh tone or disrespectful in any way.  You just need to begin to use it more often and begin to shorten the conversations among those that leave you feeling drained.  Don't worry about what people would say or think about you if you said no to them.  A famous person once said, "What other people think about me is none of my business".  People who want to say things behind your back will and you have no business worrying about them, as there are other more important things to care about in life.