I see it as follows: Infants have little concepts/constructs that can serve as foundation for thoughts. Being able to 'ground' thoughts in constructs that are u

I see it as follows: Infants have little concepts/constructs that can serve as foundation for thoughts. Being able to 'ground' thoughts in constructs that are understood helps with recalling the thoughts. At some point, the more basic constructs (the ones you created as an infant) are not as useful anymore, as your thoughts are now grounded in the more advanced constructs. This causes you to forget about the more basic constructs, as they are not used anymore; the basic constructs have served their purpose and you moved on to the more advanced ones.