Job, hobby or passion?

In my last post I summarized the answers I got on a mailing list for the short question:

what ist the fastest SQL you can create?

maybe the most remarkable answer was

I think y'all need a hobby- and one that doesn't include oracle!

Well, maybe I have to answer. Which is not that easy.
Let's try to confine a little bit: Let's start with Job. I see a job as a work which I get paid for. So i need a job to make a living.
At first view a hobby is a totally contradiction to a Job: I do it at my own will and possible even spend money to do it. A hobby is something I do to have fun.
But sometimes it's not that easy.
Even if job and hobby are a contradiction in money and choice, they are not imperatively a contradiction in fun.
Assume, you have a job which at the same time is fun. Why not enjoy this: instead of paying for fun, you get paid for! Maybe it's ok if I call it an avocation?
Of course, it's not that easy all the time, but nothing is that easy, not even a hobby ;-)
I see one more bonus in this situation: I assume I'm quite good in the tasks I get paid for. And at least at the moment I get a fair salary. I hope, both will at least stay at this level for a long time.

This all leads me to an answer:

I have a job in IT, especially Oracle. Why do I need a hobby?