A person who protects no margin eventually has nothing available when something truly important appears.

A life with no slack cannot respond. When something genuinely important appears, an opportunity, an illness, a person who needs you, there is nothing left to give and the response has to come out of something already committed. Margin is what turns you into someone who can act when it counts.

Leave some capacity deliberately unallocated, in your week and in your money. It will feel wasteful until the moment it does not. That moment is what it is for.