I know stupid people also grow old and that wisdom cannot be plucked from the air even if one has a thatch of grey hair on their scalp or no hair at all.
Both are a sign of old age and a testimony to many years of experiences gathered on earth, some by experience and others by observation. The coastal people say ukiona mwenzako ananyolewa tia kichwa chako maji forgetting that there is also the option of simply running away from being a victim of what you can clearly see coming.