Not a huge fan of people discounting ADHD as being a relevant factor here... Some things are just a whole lot harder when you have ADHD. Even doing the most basic everyday tasks can be like moving a mountain sometimes. Not saying it should be an excuse not to try, but sometimes it's helpful to hear perspectives from other people who struggle with similar things rather than be dismissed and told it's not actually a problem.
My entire musical experience growing up was shaped by ADHD, even though I didn't know it at the time. I was always extremely hard on myself because I just couldn't follow standard advice for how to practice. Motivation follows personal interest, which would change with the weather. Not to mention how much my mind would wander when I was on stage playing a solo piano piece. I aced theory and aural skills, but when it came to refining a piece of music over multiple months, I found it really difficult to stay motivated. Inability to focus ended up being the thing that made me change my major away from music in college, even though again I didn't realize it at the time - I figured I just wasn't cut out for music. (I must not care enough if I can't even focus, right?)
I didn't play music for years after dropping out of music school. Thankfully I improved my relationship with music over time, and I've gotten past a lot of the shame and self doubt that came from just not being able to practice music the same way as my peers. Had to develop my own techniques to practice effectively - "buckle down and woodshed" never worked for me.
Something I find great about having ADHD (that's relevant to this thread) is that sight reading can actually be a blast and a motivator to play my instruments. Constantly playing new things tickles my brain in a way that practicing the same few pieces for months never did. There's plenty of material out there to sight read, and it lets me play every day without getting "bored", while increasing my chops along the way.
Not sure if the dismissal of ADHD being relevant here is because of the proliferation of kids self diagnosing on TikTok lately. It's an unfortunate phenomenon, because while it increases awareness (I think a lot of people have it and don't realize if they didn't get diagnosed as a child), it gets to a point where it becomes "trendy" to say you have ADHD or etc., and then people who actually have it bad face backlash for discussing real struggles.
Or maybe some posters are old enough to be from the times where standard advice for neurodivergence was "suck it up buttercup"