What is valid is mind your business. If you meet someone in a wheelchair, do you start recommending surgical treatments or physical therapy exercises? ADHD is a medical condition, and there is no cure-all treatment or technique that will make the problem go away. You deal with someone who has ADHD with understanding and empathy. If their condition affects you, especially in a negative way (they frequently forget plans, or they are late and you find yourself waiting) then you should honestly communicate those issues. But it's not your problem to fix. Some problems can't be fixed. You're entitled to your happiness, but unless you're their doctor, you don't need to help them come up with a solution.