

To add to the other comment and give an analogy: say you’re concerned that I secretly possess keys to the back door of your house and I can freely come and go. It’s technically possible. But two questions are important; how come you’ve never seen me in your house or any signs I’ve been there? And secondly, why do me and my friends keep asking you to give us your back door key?
I think if this experience is related to having ADHD, the part that is relevant is the lack of ability to acknowledge that you’ve made a jump at all. In the example it’s a perfectly valid train of thought, but I’d expect an average person to make an effort to bring the other up to speed. Because most people generally expect to continue conversation in the same topic, you spend mental effort trying to keep tethered to that topic and have to share that rope with the other person.