When and how did you suspect you had ADHD?

I think I always knew but I had people tell me I had signs of adhd and I always had a very very difficult time focusing and was always anxious or way too energetic at random times. I was that kid who zoned out 24/7 and fell behind in school

When I explained how often and intensly I space out through out the day and how I have constant monolog in my head with many thoughts and how I can never not move to my friend's and they looked at me like I had 8 heads because that stuff isn't "normal" I then went and got tested haha