Could you explain how boredom works with ADHD? I don't understand how I could get bored during e.g. car journeys - the view outside changes all the time from signs to read, trees to marvel at, etc, I'm probably singing a Christmas carol in my head, planning my birthday party and wondering how to make lemon meringue pie. How could I be bored when there's so much going on inside my head? But when there's many activities I could do I'll often get bored because none of them seems interesting enough.
Sometimes “bored” means “I can’t move enough and scenery is scenery, you’ve seen one tree you’ve seen them all”; sometimes it means “I don’t know what to do right now”; and sometimes it means “doing stuff is hard even when I want to do something.” From what I can tell, the neurotypical definition of “bored” is different from the ADHD definition, because our experience of what we can do that is actually interesting is vastly different.