There is an phenomenon in the פסוקים regarding the Menachot (grain offerings), that draws our attention. The Torah tells us    "זאת תורת אהרן ובניו ביום הימשח אותו....והכהן  המשיח תחתיו מבניו יעשה אותה..."  The Torah teaches us that a Kohen Hedyot (a simple Kohen) , on the first day  that he serves in the בית המקדש, brings an offering which is appropriately referred to as מנחת חינוך (an inaugural offering). In addition, the same series of פסוקים tell us that a Kohen Gadol is required to bring the  very same type of offering every day of his life, an offering known as מנחת חביתין. What lesson might the Torah be teaching us by equating , in effect, the Kohen Hedyot on the first day of service with the Kohen Gadol every day of his service?  Two possibilities come to mind.

 

One might suggest that the Torah is giving a message to the Kohen who is now embarking on doing service in the Beit Hamikdash. He is being told that he should have high aspirations and realize that he might eventually become the Kohen Gadol. Therefore the Torah tells him to bring the type of offering brought by the Kohen Gadol, as if to tell him - realize how great you can become. Understand that although now your offering is a Minchat Chinuch, in the future you might bring a Minchat Chavitin.

(On a related note, we find that according to the letter of the law, it is permissible for a Jewish baby to nurse from a non-Jewish woman. Nevertheless, the רמ"א  writes in יורה דעה סימן פ"א סעיף ז  that  it is not ideal that a Jewish baby should nurse from a non-Jew. The גר"א writes that the basis for the רמ"א is the fact that Moshe did nurse from any Egyptian woman due to the fact that he was destined to communicate directly with  G-d.  An obvious question is raised. Of what relevance is the high standard that was set by Moshe in his youth to other Jewish babies? After all, other babies are not destined to communicate with G-d in a fashion similar to that of Moshe Rabbienu. Rav Ya'akov Kaminetsky ז"ל answers,  that every parent should raise his child with a type of upbringing coupled with the hope and dream that his child will reach the highest spiritual level possible.)

 

An alternative approach to explain the equation that the Torah is making between the Kohen Hedyot on his first day and the Kohen Gadol everyday, is the following. Presumably when a Kohen is doing the Avoda in the Beit Hamikdash for the first time in his life , he does so with a great thrill and zeal. With time, the excitement most likely begins to wane. However a Kohen Gadol is meant to be so spiritually fit, that every day of his life, he feels  a similar  feeling and devotion to that which he felt  when he first brought his Minchat Chinuch. Rabbi Rivlin Shlit"a would often relate a similar thought regarding a רש"י towards the beginning of פרשת בהעלותך. The פסוק says ויעש כן אהרן (regarding the lighting of the מנורה), and רש"י there comments,  "ויעש כן אהרן- להגיד שבחו של אהרן שלא שינה".  On the simple level this means that Aharon did not deviate from the rules associated with the lighting of the מנורה .However, one might ask that the Torah wouldn't need to relate something so obvious. Rabbi Rivlin cited that one can understand רש"י as saying that אהרן did not change - his excitement and enthusiasm was continuous, even after having lit the מנורה  numerous times.

 

The value of doing  doing מצוות with a constant level of enthusiasm, as if we're doing the מצווה for the first time, is something which we all are meant to strive for.  After all, in the second portion of שמע, we say והיה אם שמוע תשמעו אל מצוותי אשר אנוכי מצווה אתכם היום, and רש"י comments  שיהיו עליכם חדשים כאילו שמעתם היום. Although attaining such a level of spirituality is quite challenging, there is section in Derech Hashem that might help us somewhat work towards such a lofty standard. He writes (Part 4, section 4, page 295), "...every single day [that the world is destined to exist] is itself necessary by divine decree, having its own illuminations, influences and states, all being essential to …attain the goal of ultimate perfection." Thus the Mitzvot we did yesterday  brought perfection to the world yesterday, and today's Mitzvot  have their own role to rectify the world today. In that sense, even when we perform a Mitzvah that we've done in the past, we should not view that which we're doing now as just a repeat performance. Just as every day of the existence of the world is unique and has its own role to play, similarly every Mitzvah is "new" and unique. If we view things in that fashion, it might be easier to perform the Mitzvot with the proper enthusiasm. 

Although we are not  all Kohanim  and  certainly not Kohanim Gedolim, we should and can have high aspirations, and should  realize that every performance of a Mitzvah is to be cherished since every Mitzvah performance  in a sense a once in a lifetime experience.