I didn't have medication for the majority of my life and I got plenty done. I just had a certain degree of executive dysfunction that's hard to describe, but manifested itself as basically losing every hobby whenever I got bored (which is not supposed to happen nearly as much).
I didn't even know it was a thing that just happened to people (and had a name like ADHD) until about a year ago. I seriously just thought I was lazy or "couldn't be fucked".
So it could totally be ADHD, speaking as someone with severe ADHD who also did not know it was ADHD for quite a while.