Childhood amnesia is said to prevent the remembrance of memories from before the ages of 2-4 years old. It is my understanding that memories from that time are still available in the mind, albeit disconnected from one's conscious thought; inaccessible. However, unlike the "normal" population, we regress into a state in which we may use the parts of our brains connected with these inaccessible memories, essentially allowing the potential for these memories to become accessible again.
On more than one occasion I have recalled memories of events happening at the house I lived in until I was 2, which according to family members are consistent with actual events (their explanations of the events actually increased the vividness of what I had experienced).
Using the comparison of an ABDLs having 'more' early memories than a non ABDL is somewhat problematic, as we have no other person's memories to directly compare our own to. Aside from this, would you say you have remarkably vivid memories of your young childhood, or have exposed any long lost memories from long ago while regressing?