There is a Seinfeld episode that deals with this situation - “The Money.” Kramer has trouble sleeping with his girlfriend… Sometimes people who are used to sleeping alone have problems like this. One of the two may be a restless sleeper or sometimes one snores. It’s possible that girlfriend was uncomfortable - possibly warmer than she’s used to sleeping or maybe just full of restless energy because this was your first time actually sleeping together. I would not throw out the relationship or sleeping together because of one bad experience. Without coming off as judgmental or accusatory, explain to her that she seemed to be restless and ask if she was comfortable. Then you may be able to find something that works. For example I tend to want a cooler bed than my wife and have problems with heavy blankets on my feet - So I sleep on top of the covers in my pajamas normally with just a light covering. If the relationship is otherwise good, you can find a solution for this.

Why didn't you just turn yourself about? Because in the grand scheme of things, in the true essence, when the core meaning is all that matters, isn't that what it's all about?

not all people know how to sleep with someone else. get a weighted blanket, it's good for snuggling and will make it harder for her to move about