1. When Hashem blessed you with peace of mind and comfort, you didn't have the simple gratitude to recognize and appreciate the source of your blessings, and you stopped serving Hashem. (Rashi here- בעוד שהיה לך כל טוב.)
2. That as a result of the gifts of health and wealth and high status you became vulgarians bereft of spirituality. (Reb Meir Simcha here- והסיבה לזה שלא עבדת הוא מחמת שהיה לך שמחה וטוב לב מרוב כל.)
3. That you did fulfill all of your Torah obligations, you did everything required, you did the mitzvos and avoided the aveiros, but you did not do it with happiness or joy (Rambam- כל המונע עצמו משמחה זו ראוי להיפרע ממנו.) One assumes that this is the din of doing mitzvos with simcha that is the subject of the passuk in Tehillim (100:2) Ivdu es Hashem b'simcha.
I am going to discuss the third pshat, that the curses stem from doing mitzvos without happiness.
Some interpret this passuk as referring to one who does the mitzvos resentfully. I am not taking this approach. Not-Simcha is different than resentment. Obviously, one who feels that the mitzvos are a noxious imposition is a Rasha. I am assuming that the passuk is talking about doing them without simcha, not doing them with bitterness.
From a technical perspective, what is the problem in doing Mitzvos without Simcha? Is a mitzva without simcha lacking a positive, a failure to achieve something positive, or is it an active negative, a sin of commission.
I A Sin of Omission, an עבירה שלילית.
I would explain "sin of omission" to mean that while the Torah requires Simcha in mitzvos, that is something the Torah tells us to achieve; just as on Yomtov there is a special din of simcha, all mitzvos require that we do them with simcha. If you don't, then you haven't done what the Ribono shel Olam expects from you.
Within Heading I, there are two possibilities:
A. Every mitzva has a requirement that it be done with Simcha. This is an overlay; besides the essential act of the mitzva, the Torah wants you to do it with simcha. If so, a mitzva done without simcha is lacking shleimus, it is somewhat incomplete. So doing a mitzva without simcha would not be like "not taking a lulav." It would be like doing mitzvos without hiddur, with bare adequacy.
B. Simcha is not a part of individual mitzvos, it is a separate requirement on people, that when they do avodas Hashem, they should do it with happiness. Doing a mitzva without simcha is a bittul of this requirement. But it is still not like "not taking a lulav." It is a mitzva to have that midda, like Kedoshim Tihyu, but it is not like other mitzvos that require a specific act.
II A Sin of Commission, an עבירה בפועל. It is not a matter of an insufficient good; it is a bad act.
A sin of commission, on the other hand, would mean that the absence of simchas mitzvos shows ingratitude and lack of respect towards the Ribono shel Olam. If you appreciated what having the Torah means, if you accepted the truth and vital importance of Torah and Mitzvos, if you realized that you don't deserve life and health and the prospect of olam haba, and that Torah and Mitzvos are an incomparable gift, then you would rejoice in doing every mitzvah. Your indifference converts your mitzvos into acts of disrespect, ingratitude, and azus panim.
This is not sophistry. There is a practical difference. Question: If you are not going to have simcha when you do a mitzva, is it better to do it anyway, or would it be better to not do it at all?
If the pshat is like IA, that the Torah requires simcha with mitzvos, and a mitzva without simcha lacks something the Torah requires with all mitzvos, then a mitzva done without simcha is incomplete. The Tochecha says that punishment can come not only for not doing mitzvos, but also for doing them without Simcha, because they are imperfect (IA). But no matter what the cost of doing it without Simcha, doing a half is better than doing nothing. Even if the pshat is like IB, that one has failed to fulfill the mitzva of Simcha, this is still a matter of not doing it well enough, but you still have done a mitzvah. The fact that you haven't developed a sense of simcha is not a reason to avoid doing the mitzva. If, on the other hand, doing a mitzva without simcha is an avla (II,) it would be better to not do the mitzva at all.
This question would not apply by most mitzvos. By most mitzvos, we don't have a choice, we can't do a cost/benefit analysis before deciding if we're going to do the mitzva. If you're obligated to do it, you do it, period. But when it comes to optional mitzvos, a mitzva Kiyumis, the question becomes relevant. For example, limud hatorah beyond Krias Shma, or wearing a four cornered garment in order to have tzitzis, or spending more time in a Sukkah, or eating more Matza, or many others, such as those that are not docheh talmud torah because they can be done by others. What if you can't do them with simcha. Is it better to not do them at all?
Here is an example of a very similar dichotomy. Torah should be learned Lishma. Rava (Pesachim 50b) says that learning not lishma is good, because it will bring to Lishma. On the other hand, Rava brings down an opinion that one who learns Torah not Lishma would have been better off dying at birth. This contradicts the other statement of Rava, which indicates that "Not-Lishma" is not optimal, but has redeeming qualities. Tosfos, in one answer, says that the former "Not-Lishma" means that he learns for a job, or for honor, or because he finds it interesting. That's not terrible. The latter "Not-Lishma" means that he learns to disparage others, to beat other people down. This is terrible, and nothing good can come of it. So you see that in "Not-Lishma" there is a case of "something missing" and there is a case of "poison." Here, too, it is obvious that one could satisfy the technical requirements of a mitzva in a way that is poison- if he does it with resentment and bitterness, similar to the Gemara (Kiddushin 31a) that Kibbud Av done with scorn is a terrible sin-יש מאכיל לאביו פסיוני וטורדו מן העולם. But, as I said earlier, our passuk is not talking about doing mitzvos resentfully. The passuk is talking about simple "Not-Simcha." What is "Not-Simcha?" Is it "something missing," like a simple "Not-Lishma,"or is it like "poison," like the man who feeds his father, but does it with scorn and resentment.
The side that it is better to do them, albeit reluctantly, doesn't need proof. More interesting to me is reading Rabbeinu Bachay and the Ikkarim and seeing if we can bring a proof as to what they hold.
Rabbeinu Bachay in our parsha, 28:47
I also saw an interesting Rabbeinu Yona in Shaarei Teshuva. He says that one of the reasons we have a seuda Erev Yom Kippur is because on other Yamim Tovim, we are able to express our simcha with a Seuda, and this is very important, as our passuk in Ki Savo teaches us. Since we can't do that on Yom Kippur, we have to do it before Yom Kippur begins.
And then there's the Sefer Hakuzari, who says (3:11)
I written about this subject in the past. See Meta-Mitzvos.
On an entirely different topic: Regarding the construction set for the Goloventzitz site in Ramat Beit Shemesh, and the heart-breakingly demented things that have been said by certain Talmidei Chachamim in and around and far from the scene. Chazal tell us
And now, for an even more entirely different topic. Someone asked me whether there is a connection between our commemoration of Adam Harishon's discovery of fire Motzei Shabbos, and the fact that we eat chopped liver on Shabbos. As a result of saying a Daf Yomi for twenty five years to a collection of talmidei chachamim, baalei kishron, and tchepoons, I'm pretty quick with answers, but this one stopped me in my tracks.
Disclaimer: It is possible that the content and tenor of this post is related to Bacardi 151.