My earliest clear memory is that of my 4th birthday, from the moment I woke up to a couple of hours later. I remember my mom telling me to get dressed up so we can go to the daycare and after to school, which I started to do and then thought “what’s school? what’s daycare?” (these I asked) “why are you my mom?” (this one I didn’t for some reason). After being fully dressed, we got into the car and drove to the daycare, I was guided to a room that’s next to the kitchen and told to wait. A couple of minutes later, I notice a light coming from the hallway connecting to the kitchen (“what’s that? why is it coming closer?”), then the nanny, her husband and my mom come out with a cake. I then immediately asked why there was a cake, I was told it’s my birthday, and then I asked what’s a birthday.
So yeah I think kids ask a lot of questions the moment or around when they start to be self-aware.
Oh, I didn’t mean to intend that we don’t have memories from before that, since we very clearly do since we know who our parents/family are, the language we speak, etc. I meant that we can’t actively recollect those memories, given a few exceptions.