|In Mexico, even baby Jesus supports the national team.|
Why? Because the Mexican team plays a game in the World Cup.
If you plan to live in Mexico, you'll have to learn that soccer (known as "futbol") is more than a national hobby. It's an important part of the culture and it's commonly referred to as "the passion." Mexicans live and breath futbol (whereas "football" is known as "futbol americano"). And people missing work or calling in sick is, if not justified, expected.
Most companies know they can't beat soccer. Instead, they place big screens on their offices and factories, so that employees can watch the game and then go back to their tasks, which is a better alternative than the employees not coming to work.
Also, it's not like you can do much. Companies know that business during the games is close to zero, so even if their employees were working, nobody else will. On the other hand, companies that produce, distribute, and sell snacks, sodas, and beer will have great business right before the game.
Futbol (get used to it, nobody calls it "soccer" here) is so big that it's starting to go into religious territories. It is not uncommon to see Mexicans pray or dress their saints with the uniform of their favorite teams.
What does it mean for you? If you are planning to come to Mexico for health care or vacations, or you are living in Mexico, find out if an important game is about to take place. Hospitals and ambulances will still be available, but small clinics or doctors who run their own practices might not. Other services, like mechanics or small stores will typically close, although big chains will not. If you have a maid or a worker, it's better to tell them not to come. Chances are they won't anyway.
In the end, futbol is one of those aspects of Mexican culture that is very different from American culture. Like everything that's different about Mexico, you might like it, hate it, or be indifferent to it, but whatever the case is, it's not going to go away.