DAE Have a one-track mind?

So, a little background which might make my situation unique-ish. I'm ADHD, i was diagnosed at 21 and have been medicated for the past 3 years. However, I noticed this behavior in myself before and after the medication, so I don't think that's a factor, though being ADHD might be.

Basically, I really feel like I can only have one major goal or thing on my mind at a time. That's not to say I can "Switch off" and focus on other things. But ultimately I get bored easily if what i'm working on doesn't relate to my "goal" at the time.

A good example is work - I sometimes go through spells where i'm REALLY focused and proud of the work I do, I put in extra hours, and I really have the goal of "I'm going to further my career" in mind. I'll do something amazing, demand raises (and get them), etc. But then, 2 weeks later, i'll be focused on my dating life and work just seems like an annoyance. Or i'll be focused on a hobby of mine and how I can do better at it. It just seems like I can only hold one ultimate "goal" in my mind at one point in time.

Kinda makes me relate to Homer Simpson, except i'm high functioning and often accomplish my goals. I just can only seem to focus on one at a time.