Why are some people so good at something that doesn't exist? We drive while talking to passengers, in fact driving is an excellent way to prove that multitasking exists. We listen to music while browsing the web or working on a project for school or a hobby ect.
I can watch a movie while designing a floor plan or an idea for an invention. In fact, when I'm in a classroom listening to a lecture from the teacher or when I'm at bible study I need to draw so I can focus. So why do some people say that multitasking doesn't exist?