Yes, and it was a rollercoaster.
In the 80s and early 90s I was pretty fanboyish about Nintendo (assuming by "fanboy" you mean like the overly-hyped, overly-personal type of fan) but somewhere in the mid-90s I shifted pretty hard to Sega. And it was the works, schoolyard arguments and such, had to "rep my team" kind of thing. Not flattering.
I was gung-ho about Sega up to and including the Dreamcast going out of production, after which point I shifted to Xbox because of Shenmue, Panzer Dragoon, and other Sega stuff going in that direction. Add that to a pretty serious dose of social influence (the cool kids were into Xbox at that point) and I ended up becoming an insufferable Xbox fan (I'm not calling Xbox fans insufferable, I'm saying some of my friends were telling me
I was becoming insufferable with my Xbox fanboyism
). I became all about the big action games, the graphics, other systems were blah, all that stuff.
And that lasted until I saw an ad for Skyward Sword.
The 1-to-1 sword control looked awesome to me, I thought it'd be a Zelda game that would speak to me after the GC-era Zelda's failed to catch my interest, so I snagged a Wii and SS on black Friday and it seriously changed everything. I loved Skyward Sword so so so much that I went back to see what I had been missing out on. Found Twilight Princess for Wii, and Mario Galaxy, and DKCR, and then I heard about this RPG called Xenoblade with great word-of-mouth and picked it up too. At the time I didn't realize the significance of being able to find a copy of Xenoblade in its original case at a store for retail price, but I had a buddy who worked at GameStop at the time and in hindsight that's the only reason why I was able to.
Xenoblade was so incredible that it changed my whole perspective on the "must have gud grafficks" and shit, reminded me why I loved RPGs as a kid, gave me Chrono Trigger feels like I hadn't felt in forever (blew my mind years later when I found out it was a lot of the same team), and fully hooked me back into the Nintendo ecosystem. By that time I already had ahold of a Wii U in preparation for whatever the next Zelda game would be, and with the lineup of games on that console I think I had pretty much just put my Xbox away as of like 2012 or 2013.
Then with the Directs and the NOA skits and the Reggie/Miyamoto/Iwata trinity, I was really fully back into loving Nintendo. Was an absolute goober about how amazing Nintendo was, gushing about them at work, all that shit, just like when I was a kid. Only recently with the sanitization of Directs and the pulling away of developers from public-facing stuff have I sorta softened back into simply being a normal fan. And honestly I dunno if I could fanboy out over any company anymore, because there's been too many situations where things change, teams change, scandals and the like pop up, and I think now I look at what they do as simply products I like, as opposed to me being head-over-heels for the company.
Which is healthier, I think.
Now any sort of factor of these games or systems being part of my personality is more about
my own memories with them than it is about me
loving the company in an almost parasocial way. Dunno if that's due to age or due to how much my tastes have shifted towards indies or what, but I'm a lot more chill about it all now.
Granted if Sega comes back with a new console I might fall back into old patterns