I'm not a parent but my niece and nephew (different parents) both go to daycare. My sister knew many of the parents at her son's daycare already, they live in the same neighbourhood. My nephew knew the children of those parents too. He had his little daycare friends before he started daycare at 18mo. My sister has lived in the same city all her life, some of the parents involved she's known for 30 years.

I'm not as close to my sister in law as I am my sister, but I know that when my niece started daycare they knew some kids and parents from the playground already.

It doesn't strike me as bizarre that someone would know people in their community who are in a similar life stage.