I was reading through some older blog posts and saw the use of the term "thought train" and realized this is probably not recognized by a random reader as it was understood when I wrote it. This is a metaphor, quite visual. It immediately conjures in my mind, a vision of being inside a train that's rolling along a landscape.
I am inside the train. The landscape is actually the renderings of my mind. The back of the train is passing things I was thinking about previously, and the front of the train is passing things I am thinking about just now.
The train can go forward or backward along the track. I can fast-forward or rewind the "tape" - that is, we can quickly have the train travel to any point along a winding track along all the things I had been thinking about.
Additionally, I can travel within the train, so I can take in a wide view of everything that was thought of for some time.
It's interesting when you realize the track is part of a mental visualization, and it can be re-laid in another manner. So instead of the track traveling along a train of thought, it can be run along a path that connects various ideas or concepts.
The track may be rearranged as a series of ideas are reorganized, or parts of a sequence are changed. Then we can run the train along the new track, and we can look around at how the new idea plays out.
It's a cool, visual metaphor for clearly thinking about complex, creative concepts in the mind.