Task: Question Answering
Input (English): Passage: After meeting in the Navy recruiting line, Al Crowthers and Melvin Jones become friends.  Al has tried to enlist before, 11 times, but was always rejected because of a bad knee.  However, he keeps trying so that he can impress women (including Betty Hutton in a cameo role as "Hetty Button").  Melvin, meanwhile, is allergic to women's cosmetics and his doctor prescribed ocean travel, so he decided to join the Navy as this was the only way he could afford to follow doctor's orders.
Unbeknownst to Al, the naval requirements have been lowered and this time he has been accepted, as has Melvin.  They are assigned to Lardoski, a bully they met in line and referred to as "fathead."
While based in San Diego, Melvin falls in love with Hilda Jones, a woman who does not wear makeup. Melvin seems to attract many women, so Lardoski wagers with Al, betting that Melvin must get a kiss from any girl Lardoski names.  Al agrees and Lardoski picks Corinne Calvet, who is performing at a nightclub in Honolulu.  The crew then get sent out on the next submarine to Hawaii, with Melvin caught on deck when the ship is submerging.  Upon his rescue he is tied to a torpedo for the rest of the voyage to avoid any more incidents.
Once in Hawaii, Al romances Corinne at the same time Melvin vies for her affection in order to gain a kiss to win the bet, which his shipmates have informed him about. Melvin is unsuccessful in comforting Hilda, who becomes jealous.  Lardoski tries to prevent the kiss by getting the shore patrol to arrest Melvin, but after disguising himself as a hula dancer, Melvin gains the kiss.  Al wins the bet (and Corinne), and Melvin works things out with Hilda. 
Question: What caused the man who wins the wager to be unable to join the Navy in the past?
Output (English): a bad knee.