My memories before 4 were a blur, but my daughter remembers falling off a Big Wheel and breaking her front tooth when she was 1-1/2. She's 17 now but she can even tell you what outfits she and her best friend were wearing that day. Some people just have sharp memories of their early childhood.
The logic here is that if you are reminded of things your brain can think you remember them. This doesn't just mean that someone can say "when you were 2 x happened" and you suddenly think "I remember x!", it means that, if for example you heard the story when you were 5, a decade later that story might now feel like a memory of the incident itself.
I can't remember exactly what age he said the cut-off was, I think it was 3ish - and I don't honestly know if this is a well-educated opinion or a proven fact, but it's definitely an opinion I'm inclined to believe, both for it sounding reasonable and for the credibility of the person who explained it to me.
Just looked up his current job, as it's been a few years since I've spoken to him. He's currently a tenured (that bit I remembered!) Senior Lecturer at the University of Sydney, and his bio page says his specialist areas include:
- Emotional Development and Social Cognition in Infancy and Early Childhood
- Individual Differences in Children's Socio-Cognitive Development
- The Inter-Generational Transmission of Social Fears
- Attachment and the 'Internal Working Model' Construct
- Children's Theory of Mind and Folk-Psychological Understanding
I'm sure most people have a few legitimate clear memories (the single one I have is indeed of a traumatic, though amusing, event) of the 4-6 age range, and of course you have your savants; it's the unusual number of people who claim to vividly recall their youth pre-3 to 4 years of age who I'm skeptical of.
A 20 year old real memory is not a recording that you have carefully preserved. It is more like a a clarisworks document on a floppy disk that you copied to a wordperfect doc on a hard drive, then to a word doc on a CD, then to Google docs, and each time you copy it you have any to reconstruct some lost details.
Rehearing and retelling the memory is critical. As such, the actual different in constructing a real memory vs false memory diminishes to kill over time.
She also thought she remembered him saying 3 years old, so 4-6yo memories are perfectly feasible, and I think most people have them. I have loads.
I don't intend to make this a political discussion, but something similar appears to have happened to Mitt Romney recently:
http://www.huffingtonpost.com/2012/02/27/mitt-romney-remembe... (warning, autoplay video)
While this was, of course, widely interpreted as Mitt making up a story to play to the crowd, it seems a much more charitable interpretation is that he heard about the Golden Jubilee so often as a child that he internalized the memory.
> "Mitt doesn’t say he was there," said the aide. "In fact, he says his memory was foggy, he 'thinks' his dad had a job there and that he was “probably 4 or something like that.” He was simply telling the story about his dad."
(And to your point about not being political - I'm an Obama fan, and I extremely dislike Romney, so I think my opinion that the HuffPo piece you linked is a load of bollocks isn't motivated by my politics!)