Lists

I've got a list of things I need to do before I fly to the UK, a list of things to do when I'm back in the UK, and a list of things I need to do after I fly back from the UK.  I do have a habit of making lists.  Am I just trying to be organized?  Is this a symptom of ADHD or autism?  Or is this a symptom of OCD?  Who knows.  I wouldn't say I compile or complete lists compulsively, but I do like the focus, control and satisfaction of checking off things on a list.  And if I write something down, then at least I don't have to stress about trying to remember it.