Why do we?

Why do we cheer for our favorite team. What has led you to cheer for Man United or the Gunners. For me it was at the age of six having to choose from a Liverpool cup or a Man United cup at my Uncles house outside of London. I choose United for no other reason that it looked cool. My Uncle then said to me that only real men cheer for the Devils! Before getting too excited that is my Uncle talking not me. Gio put your hands down. What led me to this just looking at my Man United cup from Bananas. How about you what are your reasons?