לזכות שיינדי חנה בת מלכה לברכה והצלחה בכל מעשי ידיה
Why are we fasting on Yom Kippur? To suffer?
No.
The gemara says that one should not induce suffering on Yom Kippur [לא יעבור מצל לחמה]. Yom Kippur is a Yom Tov, a happy day [as the achronim learn from the language of the Rambam ואכ"מ]. The Rambam calls the laws of Yom Kippur - "Hilchos Shvisas Esor" - it is "Shvisa", resting like Shabbos. We rest from eating and drinking.
Eating and drinking is GREAT for the body. Delicious and pleasurable. But when the soul wants to soar the eating and drinking are almost a burden. How interested is a choson in his wedding meal? He is on such a high that food is but a bother [so it was for me on my wedding day].
That is what Yom Kippur is supposed to be. A person is מתענג על השם and his tremendous spiritual pleasure is supposed to make him forget the body. Be neshomo-dik and forget your body.
Rav Charlap writes in רזי לי [page 4]:
עיקר יסודות התענית למסור עצמו לרוממות גבהות נשמתו מכל ההשפלות והירידות להתענג על ד' להנות מזיו שכינתו אשר שמה למעלה אין אכילה ושתיה ושום גשמיות
