behaviors I see in both DH and DS--uh oh

So my 17 year old DS was diagnosed with ADHD when he was 6 and he has been medicated, seen ADHD coaches, been to counseling, been to peer groups--basically, he had all the support and interventions we could provide and now heading into his senior year in high school, he is functioning amazingly well.  I want to stress how much hard work it has been to get him to that point though--phone calls and meetings and evaluations and charts and consults and appointments.  My point is to see how well he is doing now it was all worth it.  This is a kid who OD'd in January and spent 6 weeks in residential rehab and now has been clean since January 11.  He got all his grades up to Bs at the end of the year, is working a full time job as a beach lifeguard and has been promoted to manager and they are training him for a supervisor position--he got to drive their speed boat today and he was in hog heaven.  So I look at DS and contrast the amount of purposeful thought and action that has gone into him and then look at DH who got NONE of that--wow.  DH can speak fairly eloquently about what we can and should do for DS, but is oblivious when it comes to himself.  Even with all the support and intervention DS has had, there are still some things I just suspect will never leave him.  For example, he is terrible at multi tasking--if he is waiting for a game to load on his laptop, he literally sits there and waits.  I will say--hey--put some laundry away while you wait and he won't.  He literally sits there and watches the thing load.  Another--if he works from say 11-5, he will not do anything else that day--he will not do any home chores before he leaves or when he gets home.  Period.  Nothing I say or do changes that.  If something in his day changes he gets really really moody--like surly.  And his sense of time--forget it--he has no clue how long HE takes to do something or how long things take.  He underestimates terribly--everything is last minute.  He is getting better with the time thing because I impose it on him--left to his own devices he would be the king of last minute.  Now, DH--same time thing.  Zero sense of how long things take or how long he takes.  Routine--he will only cut his nails or shave one day a week-period.  No matter how much he needs those things.  Period.  DH also has terrible hoarding tendencies--he has so much stuff everywhere.  I pay $165 a month for a storage locker...filled with crap.  I wonder what he would be like if he had the help and support that DS has had.  Both of them have that thing where they have an idea in their heads of how things are and NOTHING and NO ONE is going to disavow them of their ideas.  Both of them assume they know best about anything and everything.  I have stopped offering information to either of them even when I know damn good and well that I am correct--not that I am correct, but that I have the correct information.  Most of the time neither of them even realize they were wrong.  That is super frustrating to watch, but whatever.  It's kind of interesting to see what ADHD behaviors can be modified and which may just be unchangeable.  I realize my sample of two does not allow me to make any sweeping generalizations, LOL, it's just my personal observations in my own house.  I am so curious to see how DS does when he is on his own.