the lesson we can learn from the confusion of the satan; the shofar's echo into the future

1) We do a lot of things before R"H with the intent of confusing the satan.  Some explain that the reason we don't bentch rosh chodesh Tishrei is in order to confuse the satan so he doesn't know that Rosh haShana is upon us.  The gemara (R"H 16) also talks about blowing tekiyos d'meyushav in order to confuse the satan (see Rashi and Tos for different explanations of what that means).   We don't blow tekiyos on erev R"H to confuse the satan and make him thing he missed the holiday (if the reason was simply to separate the tekiyos d'orasysa of the chag from the tekiyos of the month of Elul which are only a minhag, then it would be enough to skip blowing during the daylight hours before yom tov; the additional reason of trying to confuse the satan precludes blowing even during the night of erev Y"T).  My wife commented on shabbos that the satan must not be the sharpest crayon in the box.  Every year we do the same things to confuse him, and every year he falls for it! 

I think this is exactly the Chazal want to ellicit in order to make a point.  The gemara tells us that the satan= the yetzer ha'ra.  Every year we ask for mechila and slicha and promise to do better, yet every year the yetzer ha'ra appeals to us with the same tricks as the year before and every year we fall for it again!  If you laugh at the yetzer ha'ra for falling for the little rouse we pull, the jokes on you for falling for his even simpler tricks.  

2) Almost all Yamim Tovim celebrate something that happened -- leaving Egypt, sitting in sukkot in the desert, being saved from Haman, the victory of the Chashmonaim.  The holiday of R"H is בַּכֵּסֶה לְיוֹם חַגֵּנוּ.  We are celebrating the creation of the world, an event long past, but we are also celebrating something that hasn't happened yet, something that is still concealed and hidden from us.  R' Tzadok haKohen writes (Divrei Chalomos #14):

ומצות שׁופר בּר"ה אין הקדושׁה מתגלית בּלב עדיין והוא בּכּסה רק אח"ך היא פּועלת בּהתגלות לבּו

כל מחשבות של יראת שׁמים הבּאים ללב האדם בּכל ימות השׁנה הכּל מקיום מצות שׁופר בּר״ה 

We don't necessarily feel the full effect the shofar has upon on us R"H, but as the year goes on, it's sound echoes within us inspires.  Shofar is not just about the past, but it heralds the future, as we look forward to בּיום ההוא יתקע בּשׁופר גדול.