The sleep and dream systems can fail for a variety of reasons. Emotional trauma (like PTSD), stress, insomnia, physical illness, and a host of other issues can disrupt sleep.

Instead, people tell you to sleep on a problem. And we now have good evidence that it's dream sleep that gifts you that type of informational wisdom rather than simply knowledge.

How to Sleep: Ability to Dream May Be in the Genes Published Aug 31, 2018 at 6:59 AM EDT Updated Sep 05, 2018 at 7:58 AM EDT By Aristos Georgiou ...

Rapid Eye Movement (REM) sleep, the period in which we experience vivid dreams, was discovered by scientists in the 1950s. A new study based on rare neuronal data offers the first scientific ...