Why can’t we remember our first few years?

I begin this column on a train from Paris to London. Opposite me are a mother and baby. I don’t know them and will probably never see them again.

The baby is nine months old and called Gabriel. A genial and relaxed child, he is grinning at me and waving his soft-toy giraffe. He’s wearing bootees, white socks polka-dotted with little red hearts, pale burgundy trousers and a grey top. He seems uninterested in northern France flashing past our window, though his mother has held him up to look; but he is taken with this new stranger, your columnist.

And I reflect: is it not very odd indeed — does it not require explanation — that Gabriel will never remember any of this? It preoccupies him now. Why does a curtain come down between our memories, some very distinct and strong, from childhood after the age of three, and what happened to us before that age? Why does our infancy go into the dark, never to be illuminated again?

This, after all, was the time when the world was fresh and new and amazing, when misery was most miserable and happiness happiest, when surprise was sharpest and disappointment most intense.

The question strikes me as such a big one, and so unanswered, so little wondered about, so taken (like that mysterious thing, ‘sleep’) for granted, that there must (I muse) be volumes of research, hypothesis and explanation on the subject. So I tried googling — and there really doesn’t seem to be much. The theories I’ve come upon appear almost wholly speculative, often starting from the premise that a weakness in the capacity to retain, to commit to memory at the time, must be the basis of enquiry: as if when we’re two we aren’t properly taking it in and filing it away, but start doing so by the time we’re four.