Shavuot is the great vegetarian holiday. Custom holds that on Shavuot we eat dairy meals, and so finally vegetarians can invite themselves over to anyone's house for a meal, and not have to go through the whole rigmarole of explaining why you don't eat meat!
There are a number of explanations as to where the custom of not eating meat on Shavuot comes from. One explanation says that on the first Shavuot, Am Yisrael had just been given the Torah with all its laws of Kashrut, and we were unsure of what it meant to slaughter animals correctly, or how we were supposed to separate between meat and milk. So we ate only dairy in order to make sure we kept G-d's law completely.
On one hand this is amazing. Am Yisrael had just been given the Torah, and already we had such commitment and love for it, we were going to all lengths to do G-d's will correctly. On the other hand, (forgive me!), this strikes me as sort of classic ba'al tshuvah paranoia -- so unsure of ourselves and what we are doing that we can't even eat normally for fear of messing up.
Which is it? Love or fear? Does it matter? After all, we are supposed to fear G-d, no?
Chazal tells us that the Torah does not ever refer to Shavuot (as the Rabbis later did) as zman matan Torateinu, the time of the giving of our Torah, because Shavuot is a holiday, and on all holidays we are commanded to be happy. But G-d did not want to make the direct connection of Shavuot and matan Torah for us because He wanted us to make that connection for ourselves - choosing to be happy about the gift of Torah. This is not always a simple thing because it is, after all, quite a high- maintenance gift. And that's the key. We have to make sure we are happy about it. Fear of G-d is good if it's healthy. If it's standing in awe of G-d from a place of strength and joy, and not a place of hiding or paranoia.
There is a controversy in the tradition as to the actual date of the giving of the Torah, and therefore as to which date Shavuot was supposed to fall. Rabbi Soloveitchik, as interpreted by Rabbi Irving Greenberg in his book The Jewish Way: Living the Holidays, tells us that the only way we know the actual date of Shavuot is by following the tradition of the Oral Law. So, in celebrating the giving of the Written Torah on Shavuot, it is imperative that we also celebrate the Oral Torah - the Torah that is interpreted and developed by the Rabbis and the Jewish people.
We are partners. We have a role. We can not sit back and follow G-d's law from a place of fear and despondency. The Rabbis can not and you and I can not. We have to act. This is what the Halacha is all about. And we must act from a place of strength. A place where by not doing something, we are celebrating G-d and we are joyous about what we are not doing. TO do "G-d's will" any other way couldn't possibly be G-d's will.