Football: why be upset for something ?

Question

I have some questions concerned football: 1) why everyone make football their first priority in their life? 2) why women choose to be interested in something like this: 3) why kids (from young age) begin to play football? And lastly 4) why is people upset when their team loses and the fans react 'violently' or crying?

Answer 1

In answer to all:

Passion