I watched all the games I could. Watched every snap of the '80 Miracle Bowl. Loved the '84 NC season.
Decided early in my youth to attend BYU. Got back from my mission in the late '80s. Went down to BYU right after my mission to apply for the next semester at BYU. But I missed the deadline by only a few days.
So I decided to delay BYU until later. Met my wife a few months later. She had a job she loved in Salt Lake and didn't want to quit and we knew it wouldn't work out with her working in Salt Lake and me attending BYU. So I enrolled at the U of U. I decided to be a Computer Science major since the U of U had one of the top CS programs in the nation in the early 90s.
I was still very much still a BYU fan as I attended several football games in Provo while being a Utah student. I remember how awkward I felt in the BYU student section attending one game (I got tickets in the student section as a buddy of mine attending BYU and his roommate couldn't attend the game and offered the tickets to me.) That was my first ever experience feeling awkward as a BYU fan. After that I gradually became more interested in Utah sports, and less in BYU. Still, I continued to root for BYU somewhat up until the Cotton Bowl game for that great '96 team. But that was my last memory of ever rooting for BYU as a fan. My allegiance and loyalties came fully to the U of U after that game. It just happened. I don't remember consciously making the decision to switch 100% of my fandom to Utah away from BYU - it just happened gradually over time. But of course attending Utah was the biggest factor.
And I've never regretted it. Being in the PAC 12 is so awesome.
I don't hate BYU. I even watch some games, but my interest is only casual. Occasionally I root for BYU now if it is a game against a national power team such as this year's game against Tennessee or recent years against Wisconsin. It was cool to see those teams get beat.