The joy that we experienced on the Chag is supposed to carry us throughout the year. There is a big yetzer hara that can disturb a person's happiness, and we must not fall prey to it. The Gemara tells us that Adam and Chava had the most blissful life in Gan Eden. There were angels roasting meat for them and serving them wine. But then the nachash came along and told Chava that she was lacking. He made her feel that without that one fruit they weren't able to have she would be missing so much. Then she set her eye upon it, desired it, and ate it, and that ruined everything. They had it all, but the nachash who was the evil inclination made them feel lacking. They felt that they couldn't be happy without the one thing they didn't have. This yetzer hara plagues all of us until today. Hashem gives every person everything he needs to be happy but then he looks elsewhere and sees what others have and becomes envious and can no longer enjoy the wonderful blessings that he has. The secret to the happiness of the Jewish people in the desert was that the openings of their tents did not face each other, and thus no one was able to see what the other one had. Someone could have the most beautiful kitchen but then he looks through his window and sees that his neighbors are redoing their kitchen and all of a sudden his kitchen is not good anymore. Today this yetzer hara has found its way into apps that contain pictures of everyone else's lives. This is bringing the nachash into our homes and destroying them. Someone could have the greatest life but the eye fools him into thinking that everyone else has everything better than him until he can no longer enjoy anything that he has. Rabbi Menashe Reizman pointed out that today even a poor man lives better than the wealthiest people from 300 years ago. Someone from that time who had it all did not have running water in his house. He did not have a shower or a toilet. He did not have air conditioning or heating. His bed was not as comfortable and his kitchen was not as equipped, yet he enjoyed everything so much. Today when we have so much more we are unhappy just because someone else has something that we don't have. It doesn't make sense, but it's the yetzer hara, and it doesn't have to make sense. The best advice is not to look at what others have but rather focus on what Hashem has given us. The same thing applies in the spiritual realms. Some people become depressed because they aren't able to comprehend the Gemara like their peers or they aren't able to give tzedaka like their peers. They must realize that Hashem expects a different avodah from different people. Someone who wasn't blessed with the highest IQ is not expected to comprehend everything. Hashem does not reward for results. He rewards for efforts. There can be two people in the same shiur and one understands everything and the other understands only half of what is being taught. Yet the one who understands half may be better off than the one who understands everything if he invests more effort than him. Someone who gives a hundred dollars to tzedaka can be considered greater than someone who gives a thousand or ten thousand. It's all relative to how much Hashem gives each person. Hashem gives everyone the exact lives that they need to be happy and successful in this world: Their spouse, their children, their living conditions, their brain power, their background. They are all carefully planned out for their success. If we could learn to focus on what we have and what we are capable of doing, we will always be happy and be able to do the jobs that we were sent here to do with joy.