That's the title of a book I bought recently. I haven't read it yet - but the title alone is worth it's weight in gold. ;-)
I don't know if there is a proper definition of play and playful out there - but here is mine:
"Play is the joyful exploration of oneself and one's surroundings/environment" (this also includes interaction with said environment).
I want to stress the joyful aspect of it here. If you are doing things because you love to do them - then that's one of the strongest and best motivators out there. And motivation means that the sky's the limit. ;-)
(Fear by the way is an equally strong motivator - unfortunately accompanied by a lot of detrimental side effects).
Why are babies and children able to learn so much so quickly?
Because they are motivated, hardwired to learn and have fun exploring everything around them.
If they are interested they focus intensely on one thing - and one thing only. They have no problem whatsoever trying hundreds (?) of different ways to interact with objects in their environment. They are exploring things from perspectives we - as adults - would never think about.
Who would voluntarily go inside a closet and pull the door closed behind them?
Who would sit under a table and declare it to be a cave?
Who would insist on wanting to lie in the trunk of the car on the way home? (I did once - and my wish was granted) ;-)
By not doing things like that - even simply lying on the floor reading a book for example - we forgo certain experiences. Our interaction with the environment becomes "dulled down" and repetitive.
Once you try a couple of new things you suddenly realize how "liberating" and refreshing they actually can be.
Give it a try - lie down on the floor and read a book down there. Or draw something - anything.
Compare that to your favorite spot on the couch or in your favorite chair and see how much more feedback the floor provides.
I'm not saying that this particular exercise is joyful - in most cases it even hurts a little because you are simply no longer accustomed to it.
But it's one of the best ways to get quick feedback from your body.
Now think of you going to the gym every week - doing the same exercises over and over again.
Not really inspiring isn't it?
Try to adopt a playful attitude here too: do the exercises differently - with your eyes closed for example. You'd be surprised how different things can become when you change them even a little bit.
There are restaurants now that have no lights. The staff are blind and the food is served - and eaten - in total darkness.
Since taste is integrated with our sense of vision the food tastes completely different.
Shake things up to keep them interesting and fresh. Brains like novelty!
As for chronic pain: in order to re-wire the brain you need attention and motivation. Those two ingredients are the best recipe for quick changes.
So find movements that you like, ways to do things that you like - set the mood - and go play!