Excerpts from song

1. Come to decide that the things that I tried were in my life just to get high on.
-This person isn't strong enough to get past the need on his own.
2. When I sit alone come get a little known but I need more than myself this time.
-When this person sits alone he contemplates what's wrong and realizes he can't get over his addiction on his own.
3. When will I know that I really can't go to the well once more time to decide on
-If nobody else is around he won't know when the next time may be his last.
4. Step from the road to the sea to the sky and I do believe what we rely on
-This guy believes that no matter where he and other addicts go they rely on others.

In my opinion, the singer is singing about how important the collaboration of another person is to getting over an addiction.

Why the song's about addiction