Gymnasium
To dream that you are in a gymnasium indicates that you need to apply what you learned and incorporate it into your daily life. Alternatively, the gym may be telling you that you need to get more exercise.
To dream that you feel guilty about something, relates to how you are handling your successes and failures or competence and incompetence. You may feel undeserving of your achievements. Or on the other hand, you feel that you have let others down. Alternatively, the dream is symbolic of repressed and negative feelings that you may have about yourself.