Your Time of Visitation

Many people do not know their day of visitation. They do not bring out their bucket whilst it is raining. It is when the rain has stopped, that they will realise that they could have stored water in their bucket free of charge, by just putting it under the rain. They are busy practising religion, whilst time is flying. It is a tragedy for a person not to know his time of visitation and to miss it. Why do people not know their time of visitation?