It can be because of anxiety, guilty feelings and/or stress. And sometimes it shows that you have trouble that you can't tell anybody about.
Taking a stressful exam
You may be feeling incomplete in some areas.
You may have some problems that you must face. Landing on the floor shows that you will overcome the difficulties.
You may have time management difficulties in real life.
Being naked in an open public space
You feel defenseless or you want to find yourself.