I like your metaphor for this week's parsha, of a parent teaching a young child. Emphasis should be on the word "young." Setting out a "blessing and a curse" is what may need to be done to teach a very young child. But we soon learn that the real world does not work that way: we are not always rewarded for being "good," nor punished for being "bad." That is the conundrum explored in the Book of Job (without resolution).
That moral education is supposed to continue, until we internalized those lessons, without the need for rewards and punishments. Apparently, forty years in the desert was not enough, nor even the thousands of years since. We still haven't grown up.