"Repping" your hometown

I was just wondering what makes people rep their hometowns to the point of ****, as if they had any control over their birthplace, especially when they move somewhere else for school or something. Let's say you have lived in a certain area until 18 and then you move to another area for college, do you have the same right to rep your area if you were born in an area and then moved 3 years after birth somewhere else, and then moved again and again? And what about the people who grew up in one area, then moved somewhere else to rep that area because they thought it was better than theirs. Also why do people rep football teams and such that they obviously have no control over? I'm just wondering peoples opinions about this

i'm here reppin' the one and only best state in the USA.... M-A-R-Y-L-A-N-D Taking ova the world fa sho...we rolein' deep, can't no other state be like the big MD, **** here to real, to gansta to have a copy cat... M-A-R-Y-L-A-N-D MD til the end!!!