Psychologist Dr. John Huber of Tripsitter.clinic, in fact, says that's impossible. Your earliest memories from childhood may not have really happened. "It's is physically impossible before the age of 3 and a half because the neurological processes don't start till the age of 3 and a half and it can take up to 6 and a half years of age before those centers develop!" Dr. Huber says if the story really did happen, you had heard it many times from family members and friends and it became yours as well. If it never happened, your later childhood imagination gathered bits and pieces you had heard and formed your own fake memory. And that "remembered incident" can last you for years!
"What you get are story lines about what happened to you by everybody around you. People 'planted' that story!" He also says that later in childhood a child's imagination can weave things they have heard together into an incident that never even happened.
The bad thing, Dr. Huber says, is that it's very hard to tell which was real and which was fabricated!