If yes, what do you do to feel better?
Most Helpful Girl
It rarely happens to me.
It can be many things and sometimes it is just the brain processing information. Stimuli can trigger associations to sad events.
Smells and sounds are common triggers for memories. You might not notice it, but a smell could remind you of both happy and sad events.
If the sadness doesn't last for a long time, then I wouldn't worry too much about it. Pay attention to when you notice yourself feeling sad. See is there is anything that is common every time.
Perhaps it is a place you pass while walking, or a particular time of day. These can give you a clue as to why you feel sad suddenly.
Wishing you the best of luck.1