Professor Nedergaard made an analogy to a house party:

“You can either entertain the guests or clean up the house, but you can’t really do both at the same time.… The brain only has limited energy at its disposal and it appears that it must choose between two different functional states—awake and aware or asleep and cleaning up.”

Far too many of us have been doing too much entertaining and not enough cleaning up.

-Thrive: The Third Metric to Redefining Success and Creating a Life of Well-Being, Wisdom, and Wonder by Arianna Huffington