I'm not sure. But an important part of the creative process is play. At least for some scientists.
It is hard to maintain as you get older. You get less playful. But you shouldn't, of course.
I have a large number of entertaining mathematical type of problems, little worlds of this kind that I play in and that I work in from time to time. . .
Everything, well, not everything, but lots of stuff turns out to be useful. You just play it out.
Exerpt from Leonard Mlodinow’s “Feynman's Rainbow”