To be a “loser” is not to have lost. To be a “loser” is to think YOU are the victim and everyone else is the victimizer, regarding anything negative that ever happens in life.
A loser is someone who thinks that he is always right, and everyone else is always wrong. This involves a collapse in objectivity that makes success impossible.
The loser has, above all, a fatalistic attitude about life. It’s as if other forces are determining everything. The “other forces” may be supernatural, political-social, or emotionally vague (usually the last). The unhappiness that follows stems from this error.