The tempting shortcut
Two things move together. One seems to explain the other. A neat story appears. But correlation can come from direct causation, reverse causation, shared causes, selection effects or pure chance.
Structure before certainty
Causal thinking starts by drawing the possible system. What could affect what? What variables are missing? What would have happened otherwise? The chart alone cannot answer those questions.
The practical lesson
Treat correlation as a clue. Then look for design: experiments, natural experiments, timing, mechanisms, controls and robustness checks.