I've been having them for maybe 4 years now on and off, they mostly have to do with media (shows, etc) and i compltetely drop it within like 1 week to one month. Now sometimes when I get into something I think "oh this is this summer's hyerfixiation huh?" not negatively, it's just gotten to a point where i can assume it's gonna be a hyperfixiation. I was curious and i looked it up and i saw people saying it was a form of autism, adhd, and even some mental illneses. I'm not concered if i have any because it's not that important to me. But is it true that not everybody has this? Just some thoughts.
I think you should consider why the hyper-fixation occurs, and if it's affecting your life negatively. When something becomes an unhealthy obsession, to the point where it's detrimental to your friendships/relationships/ causing you money problems etc. then you might want to consider getting help. Otherwise, I wouldn't stress over it too much. Personally, I also experience interests that I get fixated on. Some last longer than others. It can vary a lot, sometimes it's just for a few days or weeks, but then there are ones which last for years. Or I get interested in a story, but only one particular part of it which I speculate on for a while. It can be a symptom of the conditions you mentioned, but as an isolated trait by itself it's not much to go by. No one here is qualified to make that call, and even a professional would need more information to figure out if a diagnosis would be suitable or accurate. Conditions such as ADHD and Autism are made up of a cluster of traits, how they present in individuals with these conditions can differ from person to person. Especially since neurology is such a complex topic with a lot of variation.