Is dreaming just a warm-up for being awake?

NYT: Is dreaming a way for the brain to warm up for the sights, sounds, and emotions of being awake? "It helps explain a lot of things, like why people forget so many dreams… It's like jogging; the body doesn't remember every step, but it knows it has exercised. It has been tuned up. It's the same idea here: dreams are tuning the mind for conscious awareness."