Priorities

How do people set their priorities? I like to think in my mind it comes rather naturally, therefore placing things in categories as to how one feels about the things in that category. Confusing, I know.
Okay. Let's put it this way. Say you have a friend who has his/her priorities messed up. Things just don't fall into natural order, you know? For instance, say that friend has the following priorities:
1. self
2. self
3. self
4. play time
5. work
6. family

That doesn't seem quite right, does it? Especially if that friend has a family he/she should be 'worried' about. Nonetheless, that is the natural pecking order of this friend's life. How would you go about getting that friend to really listen to you in regards to re-prioritizing his/her life? No amount of advice seems to work. The friend ends up getting defensive and basically throws up his/her hands to say, "Fine. I'm just such a horrible person, aren't I?" Well, yeah, pretty much.