A pencil isn't the only writing utensil but is the only one that lets every mess-up from big to small be forgiven. If it's a small one, it gets erased and forgotten. But if it's a big mess-up, it's erased, but you can still see the slight smudges of the pencil markings and the little pieces of eraser missing. It's just trying to remind you to not make the same mistake again like a good friend should. A pencil is long and skinny and slides into your pocket easily, but slightly sticks out, the pencil doesn't try to stick out it just does.  A pencil can be snapped in half and still does it's job. Even though there's damage, the pencil doesn't make excuses it keeps going.