We all have a lot of experience with metaphors. A practical example of some early experiences comes from my kids. When they were practicing eating for yourself, the basic mechanism for picking up something and putting it in your mouth, was pretty easy to learn. After all, they had been practicing that their whole life.

But when it got really interesting is when they got a hold of one of these (a spoon). At the same time we were also starting to spend more time at the local park, at the sandbox. And you can probably guess where I’m going with this. Every time we went to the sandbox and they got a hold of a shovel, they would use it to scoop up whatever was in front of them and put it in their mouth. It took quite a while for them to build the new concept needed for this different context.

And this is how metaphors work. You take a well known concept: a food shovel. And apply it in a new context: sand food shovel. In this example the association in the metaphor is a very physical one. This ‘sensation in my hand’ is ‘food shovel’. And over time it turned into ‘this sensation and this color in this context’ is ‘shovel’. 

Note: I can’t read minds yet, so the description of the contents of kids minds might not be fully accurate.