Ki savo

As the Torah warns us of all the bad that will befall us if we don't keep the Mitzvos, one of the reasons it gives for the curses coming upon us is תחת אשר לא עבדת את ה' אלקיך בשמחה ובטוב לבב , because you did not serve Hashem, your God, with gladness and with goodness of heart.  

It’s incredulous, wonders רב האי גאון that because we didn't perform the Mitzvos with joy, these devastating curses would befall us?!

In contrast, רבי אלעזר אזכרי זצ"ל relates in his sefer, that the secret to the greatness of the אריז"ל & the reason he was able to accomplish so much, was because of his tremendous simcha when performing the mitzvos. He explained the posuk as follows: תחת אשר לא עבדת את ה אלקיך בשמחה ובטוב לבב מרוב כל because you did not serve Hashem, your God, with gladness and with goodness of heart out of an abundance of everything. He says מרוב כל means that the simcha one gets from a Mitzva should be, מרוב כל , a greater happiness than any other pleasure in this world, greater than gold or jewels. The Mitzva has to be the ultimate happiness which was the simcha of a mitzva that the  אריז"ל had.  
Why does this simcha merit such greatness?

There's a humorous story told over by Reb Henoch Alexander about a farmer who couldn't get his son to  learn even the alef bais. He went to the big city & brought back a teacher to whom he promised great compensation if he could get his son to learn. Getting through was not easy but the efforts paid off. After a few months during which the teacher toiled tirelessly to teach this boy, he finally taught him the alef beis with the vowels.

Excitedly, he called the father to come listen to the son read. The teacher pointed to the letters which the boy read each perfectly. Then the teacher went back over them asking him what's underneath the "alef", "beis" etc. He was doing great until the teacher asked what's underneath the "hei". When the boy didn't answer, the teacher asked again what's under the "hei". Again, he wouldn't respond. The father started asking him but still he wouldn't open his mouth. Finally, in frustration, the father hit him & yelled, “what's under the "hei". The child, with a pleading voice, said to his father ,”if you’re going to continue to beat me, I will have to tell everyone that the calf you stole is hidden under the hay.

Reb Henach concluded by saying, when we can't find it in ourselves to serve Hashem with joy, it’s because there's some sin hidden beneath the surface that’s causing our unhappiness.
It’s not that the curses & punishments come because we didn't serve Hashem happily. Rather, because of the root of the problem, which is we are too entrenched in sin to serve happily. Contrast that with the Arizal who wasn't plagued with sin & therefore was able to reach the highest plateau of Torah learning & even prophecy.

Most of us probably won't get to the level of the  אריז"ל , but let's at least try to find the underlying reason why our Mitzvos are not always done with the greatest joy. Let's find what's  hidden under the hay that's holding us back from experiencing the true joy of mitzvos. Then, let us eradicate it so that we will be able to put the joy back into Yiddishkeit & doing mitzvos!