Greatness is not this wonderful, esoteric, elusive, god-like feature that only the special among us will ever taste. It's something that truly exists in all of us.
Children totally accept — and crave — family rules. “In our family we have a rule for X” is the only excuse a parent needs for setting a family policy. In fact, “I have a rule for X” is the only excuse you need for your own personal policies.