Memories, so hard to stop them flooding my mind when I am trying to sleep at night. I try to quiet their persistent noise in my head with telling myself to relax. Fortunately, for myself, I have discovered the benefit of using “white noise” which in my case is a fan that I switch on at night to help me sleep on those “my brain won’t stop thinking nights.
Sadly, being able to sleep and stop the thoughts is not so easy for many of our troops. Here is an article that addresses that issue.