Ephemeral: lasting a very short time, short-live, transitory.
I really like the idea and specially when it's applied to art. Just the pleasure of the moment and nothing else.
My studio is like a playground, but by the extension the whole world is a studio and playground!
There are many ways to create ephemeral art in the outside world. My favorite one is by the seaside piling up pebbles. Helps focusing on the sound, smells and mineral materials of the sea. And then you leave taking with you a memory and perhaps a photo!