It gives us a communal activity—both in playing and attending an event as a fan. We commune in other contexts as well, but often times we feel like “an individual in a crowd”. For example, new studies show that even as the Internet binds us in a network, it isolates us as individuals. Don’t get it wrong, the Internet is amazing, but the roar of the crowd connects souls like no video conference or chat room ever could.
The sport brings us together, and lets us relate to each other in ways we couldn’t otherwise. For example, you can get to know certain aspects of personality from the way a player plays the game.
*Is not Ronaldinho's smile and the joy he plays with infectious. When a great player makes his teammates play better, when he maybe inspires the players around him or her, that makes soccer or any sport an amazing game.