God reveals to us what is essential to our well-being. The things that He does not reveal belong to Him, and should not be sought after. They challenge us to trust Him even more.
God has reasons why He keeps certain things from us. He does not give us all the details of the good things He will do for us, so that we will not get carried away and let our guard down. He does not tell us precisely when we will die, so that we would not be devastated and shift our focus from things that are more important.
When God directed Prophet Samuel to anoint David as king at a young age David knew that he would be a king one day, but it was not revealed to him that it would take fifteen troubled years for him to sit on the throne.
God may reveal His plans for our lives to us, but choose to keep to Himself the times and seasons those plans would be accomplished. Only He knows the purpose for keeping certain things to Himself. His ways and judgments, though just, are often hidden from us, and past finding out by our finite minds.