Make a fortune sitting in the office

As the saying goes: horses don't get fat without night grass, and people won't be rich without extra money. We are ordinary white collars. If we only rely on "dead salary" as the "lifeline", not only can we not become rich, but we will always be in an awkward state of "not full, not dead". Think about it, since we cannot be a big boss who can do whatever he wants, why not use our wits to work for the boss while doing some side jobs to make some extra money to subsidize household expenses.