I don't know about an LSD trip but I've often wondered what exactly a baby perceives while in the womb or as a newborn. Their brains aren't just sitting there as a blank state so they are experiencing something. I wouldn't at all be surprised if it's very trippy seeing as infants have literally nothing to hold onto to define reality as we see it.

I often watched my newborn staring off into empty space clearly perceiving /something/