Our whole Systems Engineering profession is build around decomposition, implementation, integration and verification. And so this mystery (or miracle) of emergence is just assumed or taken for granted. I teach this stuff at the graduate level and even I am unsure how to explain why properties and/or capabilities will emerge when you put together components of a system. Even though these various individual pieces have none of the properties and/or capabilities of the larger system. It just happens.
You can’t, but you can at least appreciate the mystery unfolding before your very eyes.
There is an excellent book appropriately called, Emergence, by Steven Johnson which explores this topic in detail from a more societal point of view.
By the way, another really great exploration of Emergence was also done by one of my favorite radio show and podcast, “Radio Lab.” It's well worth a listen.