Things happen together, or one event happens after another, but this does not necessarily mean that one event causes the other. There may be other hidden factors that influence both events, or the connection between them may simply be a coincidence. Therefore, people need to consider all the relevant factors to determine the real relationship between two events instead of assuming that correlation is the same as causation.

Fallacies are common in daily life. For example, if person A lends a mobile phone to person B and the phone stops working after person B uses it, person A may believe that the phone broke because of person B's use. However, this conclusion may be wrong because the phone might have already had a problem, or it might have stopped working for another reason. Similarly, a fallacy can lead to cognitive bias. For instance, if a student wears a particular shirt before an exam and gets a high score, the student may believe that the shirt brought good luck and continue wearing it before future exams, even though the result was probably caused by good preparation rather than the shirt.