be the making of

be the making of (one)

To be a positively transformative event in one's life. He used to be irresponsible with money, but buying a home was the making of him—he's never been late with a single payment! In many ways, surviving that internship was the making of me.
See also: making, of

be the making of

Be the means or cause of progress or success, as in Marriage will be the making of him. This idiom, using making in the sense of "advancement," was first recorded about 1470.
See also: making, of
References in classic literature ?
To watch, teach, "form" little Flora would too evidently be the making of a happy and useful life.