Recognizing the difference between complicated and complex. Complexity comes from multiple layers or interconnections. It can be elegant, efficient, sophisticated. Complicated is needlessly confusing. A tangled web. Unfathomable. My relationships are often complicated, but they are seldom complex.
I mention this not to be (very) pedantic or to take shots at the op. Rather, to the question, appropriate specificity, simplifies and improves your life. Remember those complicated relationships? More than half of my arguments started with disagreeing on what ‘it’ is. How many of yours?