Dreams are a natural process in sleep. Dreams occur when our sleep is in the Rapid Eye Movement phase where this phase can progress into deep sleep or progress into the alpha phase (before waking). Naturally if we are sometimes able to remember dreams but also more often forget with our dreams, that's perfectly normal.
Dreams can also be a prediction of emotions that we feel long enough. When we often feel anxious, that anxiety can enter the subconscious and we take it to bed. Anxiety is often dissertation with a scary or scary dream as told by Burhan mas. When we are happy to be happy, then the happy and happy feelings can also get carried away in a dream, be a pleasant dream.
For your experience @nomad-magus that often dreams less fun, need to be dug again what happened to you lately. Is there a burden of thought that bothers you? What do you feel (feeling) lately? Immediately find the problem, talk to a trusted person and immediately find a solution so that the problem is not carried away in your sleep @nomad-magus