Early memories

When did you form your earliest memory?

I only ask because I swear I remember my nappy being changed which must be a really early memory. Although I can't have been less than two, surely. But is that a usual age for the first memory?

Of course, one only remembers traumatic or unusual occurances. I think I remember only it because Nana changed me, which she never usually did, and I must have hated it; maybe I didn't trust her with the safety pins - they loom large for some reason - though I don't remember being pricked!