[gwright]

I think the decomposition is important but not necessariy that you have to continue that process until you have atomic parts.

Understanding the decomposition allows you to internalize the behavior of a complex entity and thus understand and predict how it will behave in different (i.e. previously unseen) contexts.

If you avoid decomposition and instead view each entity as a one-off with its own unique behavior patterns then you are limited to memorizing the behavior on a case-by-case basis. Any extrapolation or prediction of behavior would be as effective as random guesses.