One of the distinctions I'm learning to draw when talking about ADHD is between symptomatic behaviours and coping behaviours.
An example of a coping behaviour is compartmentalising one's life, putting everything into neat(ish) boxes that don't really overlap. My friends here who read this blog might be completely unaware of my other writing or activities that I don't write about here. There are a couple of friends that I've brought with me, but not many. Likewise, my work contacts at church are very separate from my work contacts on the internet. Some of them will have an awareness of my musical performances, but most won't - I still meet people in a work context, whom I think I know pretty well, who are surprised to hear that I play the ukulele and sing.
As someone who struggles with capacity in executive functions (that's the symptomatic behaviour), this is one way of making my life more manageable for me. I can walk out of one box and into another and feel refreshed. If I've been jumping between a few boxes, I can get out of all of them and inhabit the space in between. The problem here is that in any of those boxes, one cannot help but create future obligations, it's what our society is built on. But my brain struggles with knowing when to stop creating these things because they're "not now" and the "not now" is infinite. So jumping into another box is a way of retreating from one set of obligations and catching up on another set, or getting away from the whole thing - nobody knows where you are, you're ghosting everyone.
Yesterday's conversation that I hosted included people from two big boxes. There were church people there and there were clever internet people there. And I was not only uncomfortable because they struggled to find a common ground to talk about, but also because two parts of my managed system were talking to each other, seeing other, being aware of the other's existence and in the past that has felt dangerous, because it could lead to overload, but now it feels creative and manageable because I can deal with creating new obligations much more easily and trust that I will fulfil them.
Not everyone with ADHD will use compartmentalising as a coping strategy, but they will have some other way of dealing with potential overload of future obligations. That's why many of us look different from each other behaviour-wise and you get people asking "is that an ADHD thing?" or "are you sure you've got ADHD? cos my friend has it and she would never do that".