From birth to our early teens, we have far more links between brain cells. The excess brain mass is very adaptable and allows children to learn very quickly.
But the adaptability comes with a price. The large and complex network in the brain is still busy growing and not as capable of forming memories efficiently as in adulthood. Consequently, long-term memories created in our first three years of life are the least stable and prone to be forgotten as we age.

The early childhood brain

On average, people’s memories stretch back no farther than the age of three and a half. 
New science suggests that when we move into adulthood, the brain must let go of much of our childhood.

Childhood amnesia

<ul>
<li>In the early 1900s, Sigmund Freud gave childhood amnesia its name. The most commonly accepted explanation for childhood amnesia was that children couldn't form stable memories until age 7 - even though evidence for this idea was lacking.</li>
<li>In the late 1980s, experiments revealed that children three and younger keep their memories, although it is limited. At 6 months of age, infants' memories last for a day, and by age 2, for a year. At around age 6, children begin to forget many of their earliest memories.</li>
</ul>

Our earliest memories are forgotten

Even if we do have a few distinct memories that survive the cycles of growth and decay, we can never fully trust them. Some may be entirely fabricated.
The research demonstrated that our earliest memories are a blend of real recollections, stories we copied from others, and imaginary scenes dreamt up by the subconscious.

Our memories can't be fully trusted

Studies revealed that the circuits of neurons that store our earliest memories are not eliminated by neurogenesis—the growth of whole new neurons - but that they are wholly restructured, making it difficult to recall first memories.
This means that some childhood memories are missing while others persist in a patchy way.

The restructuring of memory circuits

We called them fairy rocks. They were just colorful specks of gravel—the kind you might buy for a fish tank—mixed into my preschool’s&#8230;

The restructuring of memory circuits

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