it has been said that the devil’s in the details.
this is what wikipedia has to say about that idiom:
“The devil is in the detail” is an idiom that refers to a catch or mysterious element hidden in the details, meaning that something might seem simple at a first look but will take more time and effort to complete than expected  and derives from the earlier phrase, “God is in the detail” expressing the idea that whatever one does should be done thoroughly; i.e. details are important.
What areas of your life could benefit from added attention, a more thorough examination, or a little extra effort? Take a moment today to reflect, slow down, and even if you do nothing different, appreciate the mysterious and hidden elements that surround you.