For some reason, when I try to edit this post, it doesn't update it correctly, there's a paragraph missing:
On the other hand, whenever my mind find something interesting, I can have a lot of focus. I'm able to spend a couple of week only thinking about that issue, during that time, nothing else really matters, and I can't really get interested in anything else. I have difficulty talking about anything else with my partner (which she used to find annoying). This can be anything from a problem at work, to researching what the best video projector would be and trying to understand everything behind the technology of all models in the market place... I do have a tendency to become completely uninterested about that subject or that task after it. So, for example, recently, I suddenly became obsessive about headphones and audio gear, I researched everything about them, bought quite a few high end headphones (spent a quarter of my salary on them) but by the time they finally arrived, I was no longer interested and couldn't even really find the motivation to test them. I barely use them and they are now gathering dust on my shelf
That sounds exactly like what the ADHD community calls a "hyperfixation". If you do want to look down the ADHD path more, here's some articles and such that might be helpful. Obviously, see a therapist about all of this and get diagnosed too if this all seriously resonates with you.
I have adhd and I would suggest you get that checked out because it sounds similar to how I experience it. Also search for hyperfocus online, it is what happens if people with ADHD get interested in something! As I said in another post, I get immensely interested in a new hobby like e.g. playing DND or learning how to play the guitar for one, two, maybe three weeks and after that - nada. Except "high dopamine" stuff like video games.
On the other hand, whenever my mind find something interesting, I can have a lot of focus. I'm able to spend a couple of week only thinking about that issue, during that time, nothing else really matters, and I can't really get interested in anything else. I have difficulty talking about anything else with my partner (which she used to find annoying). This can be anything from a problem at work, to researching what the best video projector would be and trying to understand everything behind the technology of all models in the market place... I do have a tendency to become completely uninterested about that subject or that task after it. So, for example, recently, I suddenly became obsessive about headphones and audio gear, I researched everything about them, bought quite a few high end headphones (spent a quarter of my salary on them) but by the time they finally arrived, I was no longer interested and couldn't even really find the motivation to test them. I barely use them and they are now gathering dust on my shelf