that someone

Someday, someone closed to you will leave you behind.
Someday, someone meant a lot to you will go on with life.
Someday, someone you always run to will not be there to share your ups and downs.
And when the day comes, when that someone really leaves, you’ll feel the emptiness, the alienation within your soul.

And this office, the very boring place, seems more boring and empty than ever. Even the fully crowded train makes me feel more alienated. Because of that someone.