“We use up too much artistic effort in our dreams; in consequence our waking life is often poor.” Friedrich Nietzsche

“REM Sleep Stimulates Creativity”: News from the frontier by Maria Schamis Turner

“A new study into the effects of napping suggests that rapid eye movement (REM) sleep may help the brain to create associations between unrelated ideas, enhancing creative problem solving.”

This makes sense to me. The dream world not only reflects the subconscious but disentangles and make bridges between memories, imaginings, emotions and thoughts- and we bring these fusions and combustions into our waking lives-