I am a slug

I am a slug.
I used to take my own time to crawl an inch, enjoying the rocky, grassy scenery along the way.
I used to remind myself constantly to take things slowly, because I believe that the most important way to live life is to be happy.
But as I continue dragging my weight across the rough ground, I cannot help but wonder - why am I doing this; where is my finishing line?
The beautiful surrounding starts to blur into patches of red and black as the heavy weight of my body becomes significant. I shift my thoughts to the itch felt from scrubbing myself against the hard and cold concrete. The increased exertion of strength is also beginning to weary my poor muscles.
When can I stop? Somehow I know I can't. Or maybe...I wouldn't stop?
Who can tell me to stop? I guess no one could. Except...myself.
However, looking ahead, I see the bin of food with a swarm of black birds hovering above it.
Stretching my muscles, I heave a ton weight of sigh, and continue on.
Inch by inch, ache by ache.
Ah... when can I stop?