Rabbi Shimon ben Yochai's son approached Rabbi Yonatan ben Asmai and Rabbi Yehuda because Rabbi Shimon ben Yochai told his son to "go to them and they shall bless you." The rabbis said to the son: "May it be G-d's will that you should sow and not reap, that you should bring in and not take out, that you should take out and not bring in, that your house should be destroyed and your lodging place should be inhabited, that your table should become confused, and that you should not see a new year." Upon returning, the son told his father that not only did the rabbis not bless him, but they caused him great pain with his words. The son relayed the story to his father.
Rabbi Shimon ben Yochai then goes on to explain why each supposed insult was an actual blessing. After reading this, I had to wonder why this whole ordeal needed to occur in the first place. It's analogous to someone who has to explain a joke they just told you. After said explanation, the joke loses its effect. The same happens here. The rabbis already caused insult with their words, regardless of intention. The fact that Rabbi Shimon ben Yochai had to explain the intricacies of the blessing says a lot about how we choose our words.
Apparently, these rabbis did not heed the advice given in Pirke Avot (1:11): Avtalyon says: "Wise scholars, measure your words carefully, lest you incur the debt of exile and be exiled to a place of foul waters, causing your disciples to drink and die, thereby desecrating the name of Heaven." This might seem like only an admonishment for Torah scholars when dealing with their disciples. Given the extent of Jewish speech ethics, it's not that difficult to argue that regardless of status or context of the relationship, one should be wise in terms of word selection because words have the power to create or destroy. Reading the end of the passage in Mo'ed Katan 9b, we see this point reaffirmed with another parable:
Rabbi Shimon ben Chalafta took leave of Rav. His father said to him: "Go to him so that he should bless you." The blessing Rav gave was "May it be G-d's will that you should not shame others and that you should not feel ashamed." Rabbi Shimon ben Chalafta came to his father, and upon relaying the encounter with Rav, he said that "mere words he said to me," i.e., he did not say anything of significance.
In this case, Rabbi Shimon ben Chalafta did not realize he was being blessed, which is why his father had to cite Joel 2:26-27 to remind him just what a blessing he received. What are we to learn from these two cases about seemingly obscure blessings?
With Rabbi Shimon ben Yochai's son, he was incapable of seeing the blessing as a blessing because the blessing was poorly constructed. With Rabbi Shimon ben Chalafta, he dismissed what he was told as a blessing. I would argue that he was so ungrateful for what he had because it was clearer that the second parable was indeed a blessing. The problem was that Rabbi Shimon ben Chalafta couldn't see it as such. This often happens when you become accustomed to having something in your life and take it for granted, instead of being grateful for it. What both of these individuals suffer from is what psychologists call the negativity bias, which is to say that we have a greater propensity to see what is bad in the world than what is good in the world.
Rabbi Shimon ben Chalafta needed to realize how being blessed to not feel ashamed or to shame others is an important trait in Judaism, especially when we are to treat other human beings decently because they are created in G-d's Image. The first case, the one with Rabbi Shimon ben Yochai's son, makes it seem like the son was in the right, but even in this case, he bears some of the blame. Why? Because he fell for the negativity bias. He also forgot what it says in Pirke Avot (1:6), the part about which you are supposed to judge people based on their merit. The men who blessed the son were reputable rabbis. Rather than automatically take it as an insult, he should have tried to interpret the blessing in a more positive light, which was the lesson his father was trying to teach his son.
It's not easy getting over negativity bias. L-rd only knows that I succumb to it more than I care for. However, if we are to get past it and live a more fulfilling life, we need to learn how not to view things so negatively. It all starts with making a commitment of looking to view one's situation in a more positive light, which can be tricky at times. Are you willing to make that commitment to a more positive outlook?