I believe we need one at times. A bit of reasoning and reflection will do us good.
It could be about work, relationships, behavior, studies etc.
The greater freedom we have the larger is the chances to make mistakes or go astray.
The world is full of pitfalls and many if us may lack the discipline.
Example:
Too much food makes us lazy and sleepy. So over indulgence is bad, but often we get carried away and suffer the consequences. But the scales will not lie and neither the clothes that do not fit anymore.
Work/Studies:
Are we getting too complacent and neglecting our duties or procrastinating?