What is a Normal good sense?

Kant( It is the faculty of the knowledge and use of rules in concreto, as distinguished from the speculative unsderstanding, which faculty of knowing rules in abstracto. Common sense can hardly unsderstand the rule that every event is determine by means of its cause and can never comprehends it thus generally. It therefore demands an example from experience; and when it hears that this rules means nothing but what it always thought pg 103) What he means is that true knowledge is something sure and distinguishesd. Now common sense you could hardly understand it, and that it comes from a cause that can never be understand it. For example with common sense you could confirm by experience.