Memories of our being in mother's womb
Nobody has any memory before the age of two because the hippocampus structure is not completely grown yet. The amygdala, instead, is fully mature at early infancy and it’s correlated with emotional memory. But our development begins very early in our mother’s womb.
The fascinating thing is that many children have womb memories.
So, there are memories which are definitely stored somewhere in our mind and they can certainly be picked up through means of some psychological techniques, such as hypnotherapy.