ADHD

Exactly this. I did mine a few months ago and was one point off being officially diagnosed. In the follow with the doctor (who luckily is a great guy and my GP who I've known for a few years now) it would seem my masking and steps I learned to mitigate the issue were the reason I didn't make it.

For one example, out of many, I couldn't say I routinely lose things like my keys - I talked openly about my natural tendancy to but because I had mitigated it, it was not impacting my life. My keys, walker etc, always go straight in a certain pot as soon as im home, my computer stuff goes into one place, which even though it's a mess of a pile, means I can find them, my phone is always left pocket and keys/wallet right pocket, and before leaving anywhere I have learned to naturally tap them (by the way, the amount of times Ive shat myself because ive been on a call when leaving them tapped my now empty left pocket before realising is insane!).

Luckily, he is willing to try the medication regardless and said to retry the diagnosis in 6 months.

That will be tough. I've been doing it so long.