You can take a kid to an experience, but you can't make them remember it.|
Memory is a fascinating subject. We know from research that much of what we think we remember is partially or totally fabricated. The brain is still organizing itself at age three, and while those kids will remember routines and familiar people, incidents are hazy at best. I'm highly skeptical of anyone who claims memories before age 4 or 5.
Rosie is one of the brightest children I've observed. Her social and communicative abilities were advanced at age three. If she can't remember that lends more support to the idea that retrievable memories just aren't there before that age.