HARD OBSESSED with western history and fiction from the mid-2000s and for many years. After RDR1 came out it got even worse. I have hundreds of books on western history and actually wrote three western fantasy novels during NaNoWriMo. Still LOVE the time period and the history, but I don't devour it anymore. I used to have Encore Westerns on TV all day long while my kid was growing up, just for atmosphere. Western groups on Facebook helped knock me down a few pegs, though, with the rise of Trumpism and getting banned for posting actual history to back up arguments with some of the racist moderators.
Obsessed with Marvel comics in the 90s and early 2000s. Faded, came back briefly, died again. No interest in comics anymore, if ever again.
Obsessed with manga and anime in the mid-90s. Came back hardcore the last couple years. Currently massively obsessed with collecting and reading manga.
Obsessed with collecting action figures for the last four years. Suddenly decided I didn't want to do it anymore and am selling most of my collection.
Obsessed with adult fantasy novels for several years during the GRRM hype. Ice and Fire, Scott Lynch novels, Joe Abercrombie, Rothfuss, Jack Vance, etc. Obsessively devoured Robin Hobb's Farseer books and after was like "you know what? I've read enough books about white dudes with swords and horrific human cruelty, I think I'm okay now".
I've always juggled a handful of hobbies so I just switch to another when I am not feeling my current one. The only thing that I was heavily invested in for a number of years that I dipped out of entirely was Lego.
My current hobbies are broken down between consumption and creative. Something like video games and board games are largely consumption based. Luckily, there is a lot of synergy between my creative hobbies of miniature painting, terrain building, and modeling that bridges the gap and often times everything overlaps in pretty awesome ways, like when I am painting marvel miniatures for a board game. The huge overlap means I am often working on multiple hobbies at once.
I think you and I are very much alike. Any excuse to mix creativity with consumption will make me even more enthralled and obsessed with something.
I always said that if I could have ever found PNP RPG friends, I would have become massively obsessed with Dungeons and Dragons - creating hundreds of character, my own worlds and modules, furiously collecting the books, painting the figures, but I just never did so I never scratched that itch.