Answer:
It means, we all need reproof, correction and discipline.
"He who spares the rod hates his son, but he who loves him is careful to discipline him." (Prov.13:24 NIV)
"PROVERBS 13... [verse] 24. He acts as if he hated his child, who, by false indulgence, permits sinful habits to gather strength, which will bring sorrow here, and misery hereafter." (Matthew Henry's Concise Commentary)