If you can manage your symptoms and don't suffer, you don't have ADHD. ADHD has a huge impact, not only mentally but also physically and on others. For example much higher risk for Alzheimer's and accidents. It's not as great as it might sound to you to take stimulants. I wish I didn't need to take them. Yes, there are surely people diagnosed with ADHD who could do without diagnosis, but having ADHD and not being diagnosed is horrible for most people. And there are groups who suffer, because their ADHD is less obvious, such as women and older people. ADHD is much more complex and devastating than you suggest. You can't fix it with strategies, many people feel ashamed all the time, because they can't function like a "normal" person