A proverb is not a promise, but sometimes as believers we try to make it so. This leads to a form of prosperity gospel that exchanges an itemized "faith" for healing and wealth (a false gospel that is popular in the world) for an itemized "obedience" that seeks to make God do things for us. Parents have struggled with the proverb focused on training up a child, hoping that it is a promise. Wise words. Inspired words. They're just not guarantees.