If you could bring only 1 thing

[Abbey Marie]

Here's the scenario:

You are going to a desert island for a very long time. Food, water and shelter will not be a problem, but there is nothing else on the island but trees and sandy beaches. No power whatsoever, and no possibility of it. No other people or animals are there.

What one thing (as much if it as you want), do you decide to bring?

Bringing a person, a pet, or any light- or power- producing item (generators, solar panels, flashlight, candles, matches, etc., etc. ) are not allowed. No boat-building materials or tools. No flares, etc.

Please no clever answers to get around this rule. I am essentially looking for what one item you would bring to comfort you over a very long, very lonely, time.

Side note: What made me think of this, was a story about Hurricane Ike. People who refused to leave Galveston were interviewed. One woman said that she put a few things in a plastic baggie to protect them during the storm.

What precious items were in that baggie? Not family pictures or batteries. Not food.

She decided to protect some cash, her credit cards, and... her cigarettes.