Not see the forest for the trees

Den Wald vor lauter Bäumen nicht sehen – to not see the forest for the trees – is an often-used figure of speech in Germany (and in the U.S.) describing how one can fail to see the bigger picture due to focusing on the details.

This figure of speech always has a negative connotation and implies that a person does not have everything under control, is not capable of stepping back in order to assess the broader situation.

This is considered in Germany to be a serious weakness, for in their work they strive to orient themselves on universal (generally valid, admitted, accepted) conditions (prerequisites, requirements, premises, suppositions). 

In doing so Germans try to maintain a certain amount of distance from the details of their work, in order to always recognize (be cognizant of) basic structures and patterns.