Moving from Happiness to Joy

What's the difference between happiness and joy? Is there even anything?
Over the last few weeks, this is something I have been mulling over; do I want my one life to just feel good and be happy, or experience true joy?
And then I came across this great analogy: Happiness is like rising bubbles--delightful and inevitably fleeting. Joy is the oxygen--ever present.

Happiness is not a bad a thing. I mean nobody wants to live an unhappy, cranky life, right? But the thing with happiness it is closely connected to our feelings and emotions, which as we all know are constantly changing. Feelings like happiness come and go, but joy is stronger, richer, and lasting. Happiness is dependent on outward circumstances. 
Joy, on the other hand, is internal and constant. Joy is ever present, enduring, and always there if we reach out and grab it. We can find joy in any and (I believe) all circumstances that the mystery of life throws our way. Joy is a beautiful unfolding that always be found in life; while happiness is something like the waves of the ocean that are always moving and changing. 
How is that people suffering or going through incredible hardships can still find joy in their pain? Honestly that's hard to explain, its a miracle. Joy is something we find deep down inside no matter the circumstances of life. And as Christians, true and ultimate joy is found in Christ alone.
While something like a good chocolate milkshake brings some happiness, I certainly do not want my life to only full of of moments of fleeting happiness. I want to recklessly seek out and find joy everyday no matter the circumstances. I want to be able to stop and see the beauty of life. I want my life to rich and full of the lasting things that matter and make a difference.
At the end of the day, life is not about feeling good and being happy. Finding joy in all things and situations throughout life is the answer to not letting life pass you by in a flash.
Happiness. Love it when it comes.
Joy. It's the love that lasts no matter what.