self-esteem

I am still confused on what is self-esteem now.
Whenever I feel there is anything negative feeling abt myself, I can
always introspect, and learn from it , accept myself and still have a
choice to feel as I want to.

If I have a choice over all my feelings, then is self-esteem is my choice ?
Then how do I nurture it in kids, isnt it their choice ?

I am not able to put in exact words?? I woud always choose to feel
good abt myself in all the situations, if its just a choice to make.

When I feel upset, is it my choice alone. And if it is, I should never
be upset then?

kirti