"I just assumed that....."

When working with clients, I can't tell you the number of times I would hear "I just assumed" followed by a statement that usually resulted in a negative outcome.  Examples?  "I just assumed he made the appointment." Or, "I just assumed my teacher would accept my paper late."  Or, the really good one, "I just assumed she knew I loved her."  In his book, The Four Agreements, A Practical Guide to Personal Freedom, Don Miguel Ruiz writes:  "Don't make assumptions.  Find the courage to ask questions and to express (clearly) what you really want.  Communicate with others as clearly as you can to avoid misunderstandings, sadness and drama.  With just this one agreement, you can completely transform your life."  So, the lesson here, never assume someone knows what you want, you know what someone else is thinking, or that someone else knows what you are thinking.  99.9% of the time you'll be wrong.  With those odds, you stand to lose.