Ten scientific principles that apply to the study of all
       martial arts: 

          1.The wimp who made it through the eliminations on luck
            alone will suddenly turn into Bruce Lee when you're up 
            against him. 
          
          2.The referee will always be looking the other way when you
            score. 
          
          3.You will have trouble with the ties on your gi pants when
            members of the opposite sex are in class. 
          
          4.The day you leave work early to make it to class on time,
            the sensei will be sick. 
            
          5.The sensei will only use you during demonstrations for
            joint-locking techniques. 

          6.If you have to use your training in self-defense, your
            attacker's father will be a lawyer. 
          
          7.After a flawless demonstration, you will trip on your way
            back to your seat. 
          
          8.After years of training without a single injury, you will
            pull a groin muscle the night before your black belt exam. 
          
          9.In an otherwise vacant locker room, the only other person
            will have the locker right next to yours. 
         
         10.No matter how many times you take care of it before your
            promotion exam, you will invariably have to go to the 
            bathroom when it's your turn.