Goes something like this:
Sailor owns boat.
Boat has burned out light in galley.
Sailor decides to change bulb.
Sailor notices socket is corroded, decides to change socket.
Sailor notices wiring frayed while trying to change socket.
Sailor decides to change wiring.
Sailor notices galley ceiling slats are rotted while changing the wire.
Sailor decides galley ceiling slats need changing.
Sailor notices ...
this goes on and on and on and on and pretty soon, Sailor is undertaking a
major renovation of his boat because of a burned out lightbulb.