Yeah. Have you ever memories that pop up only when you’re drunk? It’s the same idea.
When you’re at a certain state: body temperature, certain state of sleepiness… every dream you ever had when your body was in that state previously, whether you were 6 yrs old, ,9 yrs old, 20 yrs old, whatever, will be a “match” for your body/mind state and will start flooding in.
I enjoy the flood. It’s fun watching them whizz by.