The gemara (Pesachim 68b) tells us that even Rabbi Eliezer who held that simchas Yom Tov is ordinarily not a mitzvah obligation required everyone to eat a seudah on Shavuos because the "yom shenitna Torah", the day the Torah was given, is a day which demands celebration. Rashi explains (d"h d'ba'inan nami lachem): "sheyismach bo b'ma'achal u'mishteh l'har'os she'noach u'mekubal yom zeh l'Yisrael she'nitna Torah bo" -- one must rejoice with food and drink to demonstrate that this day is accepted [joyfully] by the Jewish people.
R' Shlomo Zalman Auerbach explained that the Torah is an intellectual delight for all those who delve into its study -- one cannot help but be filled with joy while learning on the very day that the Torah was given! Yet, that joy is insufficient. It's not enough to have personal pleasure in learning, but as a careful reading of Rashi indicates, one must demonstrate that joy to others -- one must eat and drink and act like a joyous person. It's not enough to have internal happiness in one's learning, but on this day one must externally demonstrate that joy and love of learning so it is apparent to others as well.
R' Shlomo Zalman's point is well taken for the rest of the year as well. If you learn a nice idea, share it with your friend on the train, with your family, with your kids, with your neighbor, with the internet -- demonstrating love of learning and enthusiam for Torah (whether with a seudah or not : ) is the best way to encourage others to participate and join in Torah study as well. And in particular on the yom she'nitna Torah, an essential aspect of a true kabbalah is sharing that experience with others. Enjoy the cheesecake!