The Stuff That Dreams Are Made of

Last week I had a strange dream.  I neglected to write it down, but what I have managed to remember is sufficient to feed the question of how dreams are made.

I was working at a place which produced and shipped some food items. The dream did not specify what they were.  A young man I worked with, or perhaps supervised, was caught stealing cash. While I held him by his arm, police were called, and the Lieutenant who came asked me to type out a report. The typewriter was located in an adjacent room, and since I was still holding the suspect, and I did not wish to spend time typing,  I asked the officer if he had a recorder onto which I could speak the report.  He did, it was a small electronic memory device, and I proceeded to tell my tale.  The young man caught stealing was a long time employee who had disappeared twice before, and then re-appeared to continue his work there.  That's all I recall and that is where the dream ended, my recording of the story.

Now, nothing in this dream and nobody in it was related to any of my experiences, or any people I know or had known.  Nor, as far as I can tell,  was it related to anything I had been recently reading. So out of what brain material was the narrative of this dream constructed, I ask?