No it does not mean you are missing any mark.. What i found when i read the Bible is that i would often come to understand a passage later on. maybe days or weeks or months later.. I just kept on reading in Faith and often asked God to give me understanding.. I keep on asking God to give me more understanding.. I want to understand everything
.. but God gives us all a portion of wisdom what ever He wills.. But there is no harm in keeping on asking, who knows what God is willing to do?
This observation is not a necessary thing to understand when it comes to salvation.. Salvation is pretty basic really.. God made the Way of salvation simple even a child can understand it and accept it.. But there is a huge amount of knowledge and wisdom in the Bible beyond the simple faith that saves.. That knowledge adds a lot of strength to ones Faith.. Adds armor and gives you a great weapon to weld in spiritual combat.
While it is good to accept and embrace the simple Way of salvation.. The enemy will attack babes in Christ seeking to undermine their simple faith.. So it is best to grow in deeper knowledge of the Faith so as to be more solid and deeper in ones confidence in the LORD.. That way you can brush off the attacks of the enemy which come to look pathetic when you have knowledge..