I once knew a guy who claimed he was a huge patriots fan, then the Steelers won the superbowl and he became a Steelers fan, and now for whatever reason he's back to being a Patriots fan. His favorite basketball team is the Heat.
My step aunt usually ends up claiming to "love" whoever is winning. I've seen her be a huge Saints fan and a huge Packers fan.
There's a 500 pound guy that I've known since I was like 5. Every single year he just roots for whoever is winning the most. In the 00s he claimed he loved the Ravens, during that season when the Saints and Colts almost went undefeated he loved both of them, and after the Phillies started their run he started claiming he was a huge Phillies fan. I thought he'd finally stopped being a dumbass but then I heard him talking poo about the Colts and saying he was now a Bronco fan after Peyton got released.
I've been loyal to every single one of my teams since I was in like 4th grade. I really don't understand how some people can switch around like they do and actually call themselves a fan.