Correlation is not causation.
In other words, just because two things occurred at the same time, that does not necessarily mean that one caused the other, or even that they are related at all. My favorite example of this is while there is a strong correlation between foot growth and intellectual development in children, this doesn’t mean we keep the source of our intellect in our feet, and there are many, many other fine examples.
Correlation may indicate a relationship, but don’t take it for granted. I’ve heard tell of a professor who would put a light switch behind a screen so you couldn’t see if he was flipping the switch or not with his concealed hand, then he would raise his other arm in the air and the lights would go on and off as he moved his arm. He would then point out the strong correlation between his arm raising and lowering and the lights going on and off.
(Naturally, when asked to move away from the screen and the switch, the lights continued to go on and off with the raise of his arm because he had a hidden assistent turning the lights on and off at the professor’s signal.)