The Chovos Halevovos writes that if the Tefillah and Torah which one learned in his youth are not reexamined as he matures, then the Tefillah and Torah will remain like that of a young child. One may become an expert in the entire Talmud, Shas and Poskim, and at the same time remain with the same childish understanding of “בראשית ברא”. The same is true with Tefillah. It is possible to find an old man who still davens like a small child, because he never went back to think about and delve into the topic of Tefillah. One who does reexamine his Tefillos, however, will begin to see a whole new world of Wisdom before him that he never even thought to exist, and his Tefillos will be changed forever.