[quote=@Legend]
<Snipped quote by Nobility>

You.

<Snipped quote by Nobility>

I'll see what I can do.

<Snipped quote by whizzball1>

I would venture to say that Joy is the disease, and Happiness is the symptom.

<Snipped quote by Galaxy Raider>

Alright, man. All our hearts are with you. 
[/quote]

By that I mean that joy does not always come with happiness. A symptom almost always shows up, and is more tangible than the disease--but joy is more tangible than happiness. Joy as a medicine and happiness as a possible side effect is more representative of what happens, in my opinion.