Lower-right
子 is the child radical, originally a swaddled infant with arms outstretched. It supplies a strong semantic anchor: the survival and care of the young — to keep, preserve, save. From there
存 generalises to 'exist, store, deposit' (
存在 exist,
存款 deposit,
保存 preserve). Joins
孔,
孙,
学 in the child radical family.