While Am Yisrael traveled in the desert, Hashem provided them with Man (BeMidbar 11:9). Not only was this food effortless and plentifully available, but it remarkably tasted exactly like anything the Jews wanted it to taste like (Rashi 11:5 s.v Et HaKishu’im). Despite this, Bnei Yisrael complained over the lack of meat and reminisced about the food that they ate as slaves in Egypt. This angered Hashem greatly (BeMidbar 11:4-10).
How could a group of people who had just been freed after years of slavery, been shown miracle upon miracle, and been given everything which they needed manage to complain over such a minor issue? The answer lies in the extraordinary way in which Hashem "designed" us. When it comes to our daily thoughts, Hashem wired us in a fascinating way – our minds easily and naturally focus on what we do not have. It takes effort to think about the blessings of which we have many.
Unless we make a conscious decision to focus on something positive, our minds will by default easily drift towards negative and unproductive thoughts. The Jewish people had been given everything from Hashem: their lives, their freedom, and all of their physical needs were provided for them with little or no effort. However, instead of being overjoyed beyond belief by focusing on what they had, the Jews allowed their minds to remain barren by complaining about all the things they did not have.
Because they did not focus on what they had, Hashem knew that there was no way He could ever make them happy. There is no amount of blessings that could ever make someone happy if he/she chooses to have a negative attitude. The Pasuk tells us that there was a group of people amongst Bnei Yisrael who “Hit’avu Ta’avah,” “craved a craving” (11:5). Since they wanted nothing other than to complain, they would never be satisfied. Hashem gave them all that they could have ever needed. However, because of the people’s desire to complain, nothing stopped them from complaining.
We see throughout Tanach and history that there is no correlation between monetary wealth and happiness. Whereas Bnei Yisrael had everything in the desert and still were unhappy, generations of European Jewry remained committed to a Jewish lifestyle despite their less-than-ideal lives and constant persecution. We see that if somebody wants to abandon a Torah lifestyle, he will do so despite everything he has, and if somebody wants to remain steadfast in his/her devotion to Hashem, he/she will be able to do so, regardless of any external factors. We must be thankful for our blessings and attribute them to Hashem. If we can maintain a positive outlook on life, then we can hopefully lead happy lives in which we feel that we are lacking nothing.