Here's why:

* Not a true liquid: Porridge has a definite shape and doesn't flow like a true liquid.

* Not a true solid: Porridge has a consistency that is more like a paste or gel, it can be stirred and poured.

Colloids are mixtures where one substance is dispersed evenly throughout another. In porridge, the oats are dispersed in water, creating a mixture that has properties of both liquids and solids.

So, while porridge might feel like a solid when you eat it, technically it's a colloid!