It is normal to feel a bad mood or be upset by something, it is also quite normal to have a desire to be alone or spend the evening with your personal experiences. But this is normal, provided that you do not experience a feeling of complete despair, hopelessness and can not satisfy your needs with the help of the usual things for you.
Most likely, these may be symptoms of depression.
If the question "Tell us about any pleasant memory?", You dig into your head for a long time to find positive moments, this is an occasion to seriously think about your mental health.