Simple.

When I was young, I was quite a "normal" teleiophile, but also a pedophile. In my youth that pedophilia side was dominant, I always fell in love with 12-year old girls (now they feel very old to me).

The pedo side always existed there, though during some decades it was in the background. Then, though I'm not Casanova or Don Juan or Romeo or Remus, I got enough experiences with adult women and lost interest in them. In the course of two or three years I had lost all my interest in adult women, in fact began to feel dislike for their bodies, and my age of attraction dropped by several years.

This is not at all exceptional: I have heard many similar stories. When I reached the certain age, my pedophilia just "matured", if we use that term.