it is television. The programmers will cram 30 scene changes in a 20 second long segment. Commercials, "reality TV shows", etc. The images on the screen are present for about 1/5 of a second, not long enough for the brain to focus on any one image, before the scene changes and the next is displayed, all very rapidly. The mind is deluged with literally thousands of images even in a short time like 1/2 hour. Over time this re-programs the mind to be incapable of focusing on any one topic for very long, including studying math or other learning. It destroys the mind's ability to focus and concentrate and to have patient discussions.