What's the Difference Between Sober and Not Sober?

When you think of this process, what immediately jumps to mind for me is Delonté West. There's a photo a couple of years ago that went super viral online because he was at a red light begging for money. And so I think about like your friend who you saw on the street, you were able to get him sober. What do you think is the difference as to why one person ends up being sober and the other one does it? Is it just something that they have to want it or is there something else?