one memory that has stuck was following the builders around my house at age 4 or 5, using my pretend tools to mimic whatever they were doing (they were installing bay doors).

My first memory is my 3rd birthday and having Grape and Orange Nehi Soda in glass bottles. Blue boy candle holders, 3 of them, on the cake. It rained that day, and I lost my temporary tattoos on the front of the house, and the rain ruined them.

My first memory is probably around 4-5, when my mom argues with my father, and I tried to help my mom by screaming at my father but then got slapped by my mom. Lol, not a good idea to get into adults’ political game.

Sucking on dem teats. Unforgettable.

My first memory was meeting my parents for the first time when I was around two (I'm adopted). I don't remember anything before it, probably for the better.

You equate 'consciousness' with the brain's ability to store long term memories. I'm not sure if that definition fits.

Has anyone been able to determine at what age the brain gains this ability? I have a few vague memories from my early childhood, but I can't remember just how old I was when I experienced them.

yep i had a operation sometime back - i felt very relaxed after coming back.