All things that are symptoms of ADHD are also things that everyone experiences sometimes. It's when they become detrimental to daily life that it might be ADHD.

So it's normal that you find them relatable.

It's all a spectrum. Our minds, in some ways, are brute forcing ways to approach survival. Each individual's brain settles on some patterns that they determine work for them, and when you look at the collective, we can end up with very different ways of thinking but they are all based on balancing the number of neurons devoted to various tasks like visual processing, audio processing, social skills, various physical skills, etc. ADHD is based on how attention is tuned, both how long you can pay attention to something you might not want to and also how your attention is divided between tasks you're focusing on vs other things going on around you.

Personally, I don't really give that much attention to things going on around me. I'm usually either actively doing something or lost in my thoughts. This has the advantage of being able to think through things, but at the cost of missing things around me, which can include someone addressing me. It's pretty much an always on thing. I do hear it and my brain can often process it after I realize I've been addressed. But I'd guess that most people are like that when they are actively concentrating their full attention on a task. Or thinking, I'm sure non-ADHD people do that, too, but the balance between time spent focusing on thoughts vs processing general surroundings might be different.

Though tbh I have no real idea. My entire experience is inside my own head and I can only guess at how different things are from brain to brain (and to what level other organs contribute to that, since they've all got neurons, and chemistry that they all play a role in can have huge effects, too).

Think of it this way. Many 'normal' people can exhibit different symptoms that get associated with ADHD. With people who are diagnosed with ADHD, they must pass a certain threshold number of these symptoms and severity.

IIRC, it's a similar approach to ASD

This mental checklist of things that point to me having adhd is growing uncomfortably large. Is there anything that can point to someone not having adhd?