Assumptions are liquid. Like other liquids, assumptions take the form of whatever container they exist within. They trickle, flow, permeate, and settle. Over time, they’re absorbed into the container itself and can corrode if toxic and erode if the container is absorbent and malleable.
Assumptions are combustible. They ignite and create fires that must be handled and which damage the container. They distract from the other things within the container.
Assumptions are dense. They’re heavy and thick. They’re hard to remove and hard to clean up.
Assumptions are translucent. They allow light but not detailed images. They distort. They cloud what would otherwise be clear.