It's a tough one, because the symptoms are relatable to most ("isn't that everybody?"). They're just more intense than for most, and come with unexpected "features" like executive disfunction. The intensity also varies from a person to another, and the severity depends on a person's lifestyle.
The lack of focus is a lure, an oversimplification. It's not just "I can't focus on something I don't like to do". It's more like "halfway into making a cup of coffee, the most important thing in my life became to clean the pantry". Imagine running late, but stopping dead in your tracks with only one sock on, and answering an email. You know it's mad, but you can't help it.
However if you have a job that's lenient enough, you can hide it well. I stopped treatment because I couldn't gather enough data. My job was too easy to know if it worked. It's still the case.
Another thing is that a lot of people learned to cope with it for decades before getting diagnosed. Their life is full of alarms and error-catching mechanisms, so the symptoms are well-managed. If you know your strengths and weaknesses, you pick your battles. It's not an issue unless your battles are picked for you.