We all have human nature. Human nature is part of the operating system of the human brain common to all humans. It is connected to our human DNA. Traditions are like triggers, than push certain operating system buttons, so we all can be on the same page.
If you took a holographic slide, with can show the world in 3-D, and use a whole punch, the little circle of the slide, that comes from the hole punch, can reproduce the entire 3-D holographic image. Holograms are weird and interesting that way. Traditions allow all the individual holes punched; each of us, from the large social holographic slide; culture, to express the same image, both individually and collectively. It is part of the brain's IT, connected to its 3-D firmware; spatial thinking.
Not all traditions work as well to make all the hole punches, and the entire slide, appear the same. The ancients were better at this since they were more right brained. We modern humans tend to be more differential; ego and this degrades the 3-D hologram to, at best, a 2.5-D spatial image.
The 2.5-D spatial image is less enduring and is not exactly a hologram. A spatial image is like a 3-D image expressed on a 2-D flat surface; cause and affect, using shadowing and highlights. It can fool the eyes but it can not get past the sense of touch.
As an experiment, touch your screen below to see that this 3-D image is actually flat and therefore not a 3-D holograph. A hole punch will only show a part.
There is another type of spatial illusion that was expressed in the art of Escher, as show below. This art work below is called Relativity. It shows a 2.5-D spatial illusion that appears to show that all staircases are relative; relative morality. Each staircase and walker, by itself, seems to be fine, but when they are all placed side-by-side, as in the art, they cannot all be right at the same time. In this case, we may use gravity to become the final litmus test, with not all the staircase orientations able to satisfy this primal need. This type of affect is common fad traditions, that may work in the short term. One can come to a focus by suppressing others; look at one staircase, but this won't give the full 3-D buzz that humans crave.
Christmas is 3-D holographic tradition because it triggers the timeless joy of a new child; part of human nature. This is part of out collective human nature from time memorial. It brings out that need to love, share and protect. The child firmware will also help people tone down the stresses and anger of adulthood, since babies need soft and understanding joy, even under tough conditions for the adults. This was well designed to push buttons for a month, can also unite a huge team, whose little holographic punch out, is part of the same larger collective holographic slide.