i agree with the fact that early childhood defects or illness
can damage the brain cells of the child, causing the child to be
psychologically weaker in terms of learning and processing of
thoughts.
but i also disagree that this would remain forever the same.
because, i believe that when a child grows up, he has the choice to
choose between putting in the effort and giving up to his current
fate. but shaping one's mentality, he can do many things
successfully if there's a will power to achieve success in general.
there's no definite limit a brain can do. if handled well, it can
do wonders, beyond anyone's imagination.