Contrary to what was always believed, dreaming provides good stimulation for the brain.
While it was believed that having a "head in the clouds" meant a slowdown in cerebral activity, a study published in the Proceedings of the National Academy of Sciences demonstrated the contrary.
Daydreaming stimulates activity in the brain, especially when it comes to complex problem solving.
The study was conducted with magnetic resonance imaging (MRI), demonstrating that those who daydream experience a greater level of cerebral activity than those who focused on a specific task.
Hence, dreaming is good for problem solving.