Everyone puts things off sometimes, but procrastinators chronically avoid difficult tasks and may deliberately look for distractions. Procrastination in large part reflects struggles with self-control as well as the general human inability to accurately predict how we will feel tomorrow, or the day after.
Perfectionists are often procrastinators; it is psychologically more acceptable to never tackle a task than to face the possibility of falling short on performance. Many procrastinators may contend that they perform better under pressure, but research shows that is not the case; more often than not that's their way of justifying putting things off. And the contemporary environment abets procrastination by supplying an array of distractions, electronic and otherwise.
For procrastinators, "I don't feel like it" takes precedence over goals; however, it then begets a downward spiral of negative emotions that further deter future effort. Procrastination also involves some degree of self-deception; at some level, procrastinators are aware of the truth of their actions.
The bright side: It's possible to overcome procrastination—with effort. Changing behavior consumes a lot of psychic energy, but engaging in highly structured cognitive behavioral therapy is one approach that has worked for many.