Code written by people who don't know 1 and 2 tends to make the mistakes that you learn to avoid by learning 1 and 2. And these are mistakes that you can make a

Code written by people who don't know 1 and 2 tends to make the mistakes that you learn to avoid by learning 1 and 2. And these are mistakes that you can make anywhere in your code and that can be very costly in performance and correctness.