I went with my parents when I was 9 and remember very little - tiny snippets of our hotel (off site), watching Liberty Belle Riverboat while eating Nachos, and being rained on in Epcot.
I remember no rides, no meals, no character interaction.
I also went when I was 14 and remember barely more than that - just riding Splash, the massive crowds, and the monorail to Epcot.
So...I don't think you can put a good age on it.
I say start them super young so that the memories build.
I should have added that to my response as well...I went at 7 and 12 and have a few specific memories but really the memories are more from looking at our old photos and videos. But, I know I fell in love with Disney as a child so obviously the "in the moment" moments had a profound impact on me.
I do remember being at the Polynesian and Contemporary (just visiting because we were staying off site) and thinking how lucky the people were who got to stay there...and vowing to stay on site when I was older....which I always have, lol!
I should have added that to my response as well...I went at 7 and 12 and have a few specific memories but really the memories are more from looking at our old photos and videos. But, I know I fell in love with Disney as a child so obviously the "in the moment" moments had a profound impact on me.
I do remember being at the Polynesian and Contemporary (just visiting because we were staying off site) and thinking how lucky the people were who got to stay there...and vowing to stay on site when I was older....which I always have, lol!