Then the teacher tells you that most professionals don’t code this way anymore.
So you start learning about classes, and instances, and instance variables, and methods, and inheritance, and a whole bunch of other object-oriented programming concepts.
Then you try to unlearn the way you originally learned to write code, and learn to write code in the new object-oriented way.
Missing next line: "Then you get a job and your colleague tells you that most professionals don’t code this way anymore.