The container metaphor is one of the most important and deeply ingrained metaphors in the human cognitive toolkit. Take the example of being “in love” with someone. This metaphor uses container logic. I always get a kick out of literally imagining a metaphor. When I visualize the “in love” metaphor, I imagine that falling “in love” is like someone stepping into a box that is labeled love. When you are in love, you are in the box; when you are not in love anymore, you are no longer in the box. It’s a simple metaphor, but very powerful, since it compels you to think of love as an on-off switch, since objects are usually either in a box or not in a box, but not often only half-way in the box due to gravity. So when we say “I don’t just love you, I am in love with you”, this is a powerful expression since it signifies the presence of a powerful, not lukewarm, feeling. It means you are fully immersed in the love box. But I suppose the container of love doesn’t have to be a box. There are a lot of things you can be “in” besides boxes. But the box-logic is I think more pervasive. Think of how naturally a young child takes to container logic from the interactions and observations of boxes being used. They understand what it means to place something in a container. They watch milk being poured into a glass. They watch the toy going into the toy box. They crawl inside giant cardboard boxes. Children are probably exposed to the human use of containers many times a day, every day. It’s obvious why such a metaphor would be deeply ingrained in our minds. Containers are one of the greatest human inventions. A wicker basket to help you forage more efficiently would have had helped families gather more food to better prevent starvation in their young.
As Lakoff and Johnson point out, container logic is also helpful for imagining logical schemas stemming from “inclusion” e.g. Container A is inside Container B and Entity C is inside Container A, then Entity C is inside Container B. Moreover, container logic is probably most important in grounding how we think of our own minds. It’s fairly natural for an English speaker to say things like “He has a great idea in his mind”, “I’m feeling out of it today”, “That went over my head (didn’t go into the box)”. We imagine memories being “stored” in our minds as if our mind was a storehouse of goods, with separate rooms or containers for each memory trace or idea.