Comment by P_I_Staker

It presents in different ways. Someone isn't having 5 conversations, but could be drifting in and out of thoughts. It might just look like they aren't very interested. If it's more severe you would have more trouble controlling these kinds of things for a number of reasons related to the condition (poor executive function and impulse control).

I've met "people with ADHD" who seem to not have the condition at all, though pretty much always medicated. On the other hand, I've met people with far more clearcut symptoms, and I felt like I had way more in common with them. It sounded like they were living the exact same life.