Why the hell does this keep happening? I still hear horror stories of how people struggle for half of their lives and nobody stops to think "this isn't normal, we should see a doctor" and it just infuriates me.
Please, if it is negatively effecting your life or you get into arguments about it and it's effecting your social or home life, see a doctor.
I didn't get diagnosed until just last year, and I'm in my early 40s. While this new knowledge has certainly had a significant impact on my life, I can't help but wonder how different my life would have been had I been diagnosed in the 3rd grade when I came home and point blank asked my Mom if I had ADHD... spoiler: she told me no.
It's hard to let that go.
Almost the same age as you and I'm fairly confident I'm undiagnosed and have been since about 3rd grade as well.
My mom had such a diagnosis suggested to her multiple times but felt the stigma of a diagnosis and a medication to treat it was worse than just doing nothing. In her mind, I'd get diagnosed, given a label that would prevent me from ever getting a job or having a normal life, and drugs I'd take for the rest of my life that would make me act like I'd received a lobotomy.