What is the scientific explanation for dreaming?

One night when I had extremely vivid dreams, the next morning I felt really refreshed. And I could remember the dreams very well. Based on my personal testimony, my theory is that having dreams is like booting your brain. Vivid dreams especially are the brain's way of dealing with all the unnecessary bullshit that you've caused it to deal with. It's like shutting down all the programs that are running on the background wasting energy and restarting the system. Those things could be stress, anxiety, overthinking too many subjects at once, etc. When the brain starts a process of shutting those things down when it's too much, it manifests as dreams.