The analogy becomes less helpful when its decoration requires more explanation than the original idea.

A comparison earns its place by making something easier, and it stops earning it the moment you have to start defending the comparison. Elaborate metaphors tend to grow parts that do not correspond to anything, and then the listener is working on two problems instead of one. You can usually feel this happening: the extra sentence beginning ‘well, not exactly like that’. At that point the plain version would have been quicker.

When you explain something this week, try the direct account first and only reach for a comparison if the direct one fails. If your image needs an image of its own, drop it and say the thing straight.