First of all, you may suddenly wake up in the middle of the night because you sleep too much during the day. Many people have the habit of taking a nap. If you sleep too much during your nap, you may suddenly wake up in the middle of the night and then you can't sleep.
The second reason may be that your bed is too hard. Many people just put a mat on their beds because it's summer. When they sleep at night, they feel that the beds are hard, and then they can't sleep well or suddenly wake up in the middle of the night.
The third reason is that the ambient temperature is too low. If you suddenly wake up in the middle of the night, you can see if the room temperature is too low. Because it is summer, many people sleep with air conditioning on, so they may be frozen in the middle of the night.
The fourth reason is that you can ask yourself if you want to drink coffee at night. Many people have the habit of drinking coffee at night. Drinking coffee will make them more excited. You can ask yourself if you drink coffee.
The fifth reason is that you are too energetic. Many friends have nothing to do during the day and can't use up their energy. They may suddenly wake up when they sleep at night. This is my experience, I hope it will be useful to everyone.