Idle Brains are very active and basically play vs themselves. The lack of enough boredom can be very dangerous. People keep staking thoughts and emotions in their subconsciousness and become truly mentally restless. That disturbed my creativity and sleep in my mid 20s, until I solved it with a decent amount of meditation.
It is interesting that you mention the sleep thing. When I was mid-20s and early 30s, I had a lot of trouble sleeping also, until I realized what the problem was - I wasn't thinking enough. I consumed a lot, but didn't go deep on much at all and barely created anything. Now - there are no issues whatsoever.
It's very easy to constantly consume something, what an interesting problem.
And, it makes us feel like we are doing something of value whilst consuming, while actually doing nothing at all. Very interesting issue.
Consuming and creating is the exact opposite, but only one of those is putting actual energy into the system.
Consumerism, the killer of creativity.