Oh, self esteem can be build up from anytime, not just from baby
stage. Remember Emma, the mummy who became a (police) counstable?
She was a wreck 2 yrs ago after her breakup, but now she scored
high on self-esteem.
The point made was: success can help to boost confidence and hence,
self-esteem. I agree with this, coz in the old days, how many of us
as babies actually got much attention from our not-so-well-educated
parents? Many of us were also shy and lacking in confidence. But as
we grow up, we learn, gain more experience and began to get a sense
of who we are and become less afraid of what others say or think
about us.
If you're serious about boosting your self-esteem, the immediate
task I think you can do is study hard and do well for your coming
exams. Good results are always a good morale booster. 
