He probably doesnt remember anything. Its like after hes done competing at a regions championships and he goes to sleep, his mind gets wiped.
I mean he still..... STILL doesnt know how to catch a Pokemon the right way nor does he ever really pay attention to type advantages.
For instance, with Iris and her mocking him all the time, why doesn't Ash just get in her face and be like, "Hey annoying, ignorant little girl... Ive won 40 or so badges in 5 different regions. Im in the Orange Island HOF! Ive seen every legendary Pokemon there has ever been and Im pretty sure I saved you and the rest of the world from utter destruction at least 13 times. So do me a favor and back the **** off, k?"
But no.. nothings ever mentioned and he continues to go around and act like an idiot most of the time. Ash is just full of face palm moments.