Uhh, I'll do my best.

At its simplest, in the West we have a thing for threes. Three bits of God, three little pigs, three branches of government (in the USA at least), "things come in threes", three books/movies in a series (a trilogy), stories that have a "beginning/middle/end".

Bottom line, the West tends toward organizing and thinking of things in threes. Some might even be superstitious about threes (perhaps a Pythagorean influence).

In China the number 4 plays a similar role. I don't know much about 'numerology' in China, save to say that recently the number 4 (which apparently sounds like 'death' in Chinese) has been considered bad luck. Here's a better explanation than I could give: https://www.quora.com/In-Chinese-culture-why-is-the-number-4...