Neither of my kids went to preschool and they are both high achievers. Stressing is not necessary, they all catch up as soon as they are ready. My son went into kg without knowing his alphabet. I thought he was slow and that he'd have to repeat kg, but he learned them within weeks of starting and he's the second highest reader in his 4th grade class. He read Harry Potter at the end of first grade!! I was a stay at home mom so he didn't have that structured time and the interaction that other kids had, but we had lots of play dates and lots of hands on instruction from me and the social stuff came easily for him as soon as he went to school. He's a social butterfly now. Relax and see what you can find, if it's nothing, that's okay too. No kids get kicked out of kg because they don't know how to say their abc's or to sit in a circle. He will learn it as soon as he encounters it and he will be better off for not having been forced into it too early. Most kids aren't ready for such structure at 3 & 4 so be thankful he's not being forced into it too early.