Everything Madoosa says, and... Even for PG people, it's quite unusual to remember in accurate detail how things were when you were 2.5. Do you think your SO really can, or is he maybe mixing in memories from later? Are his parents around to ask?

Fwiw, my DH also persisted in thinking DS not so unusual after it was clear to everyone else that he's seriously unusual. Wishful thinking, in a way, I think, combined with fathers often getting little exposure to children other than their own.

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