Let me count the ways.

The following are the most common reasons people procrastinate as listed by David Burns, MD, in his book Feeling Good.

You are frozen in the present moment, forgetting that things were better at one time and not believing that they will be better  in the  future.  You feel your lack of motivation is  unending and irreversible.

You are convinced that your moods are caused by something  beyond your  control:  fate, hormone cycles,  disease,  genetics,  other people's evaluation of you, etc.

You  jump  to the conclusion that action will not make you  feel better because you are in the habit of saying, "I can't" or "Yes, but...."

You  feel that the effort to complete the task (almost any  task) would  not be worth the rewards. Your blue mood makes  you  feel that  nothing counts or is worthwhile. This torpedoes any  sense of fulfillment or reward.

You  think  that making an effort and not succeeding would  be  a great personal defeat so you refuse to try at all.

You may also evaluate your performance strictly on the outcome of an  event, rather than your personal effort during  the  process.  

All  you can control is your personal input to the  process,  not the outcome. Once you concentrate on the process rather than the outcome, you can learn from mistakes and attempt to correct  them in  the  future. This keeps your self-esteem  off  the  emotional roller coaster of outcome.

You feel that any success is based on chance and you can not keep up  that  success.  When  it comes out that  you  are  really  a "loser,"  the  rejection and pain will be worse because  you  did succeed.

You may also fear success because you anticipate that people will make  even greater demands on you after your success. Since  you are convinced you must and can't meet their expectations, success would put you in an impossible situation. Therefore, you try  to maintain control by avoiding any commitment or involvement.

You  imagine that if you try something new, any mistake  or  flub will  be  met with strong disapproval and criticism  because  the people  you  care  about won't accept you if you  are  human  and imperfect.  The  risk of rejection seems so  dangerous  that  to protect yourself you adopt as low a profile as possible. If  you don't make any effort, you can't goof up!

You feel under intense pressure to perform--generated from within and without. This happens when you motivate yourself with moralistic "shoulds" and "oughts." Then you feel obliged, tense,  resentful  and  guilty. Each task becomes so unpleasant  that  you can't face it. As you procrastinate, you label yourself as "lazy" or "no-good." This further drains your energies.

You  feel and act as if you were entitled to success,  love,  approval, health, happiness, etc. Instead of persisting  patiently over  a  period of time, you go into a frenzied  state  of  panic and/or rage when life presents you with obstacles.

Your  frustration  results from your habit of  comparing  reality with  an ideal in your head. When the two don't match, you  condemn  reality. It does not occur to you that it might be easier simply to change your expectations than to bend and twist  reality.

This frustration is frequently generated by "should" and  "ought" statements.  While  walking, you might complain,  "For  all  the miles I've walked, I ought to be much thinner by now."

Indeed?  Why should you? Are you entitled to loose a pound  for each mile you walk? Why? Maybe the reality is that you will not loose a pound for each mile you walk, regardless of the ideal  in your head.

This  internal talk just adds to your sense of futility and  increases your urge to do nothing.

When  you are frozen in the conviction that you have let others down, you naturally feel unmotivated to pursue your daily life.