Technical question: He states that you should look at a pattern, look away, and then check to see if it changes. Supposedly it will change because your memory can only hold 7 +- 2 bits. Now if your memory is too small to keep this supposed pattern consistent, how the hell are you supposed to memorize this pattern for a consistency check? I.e. you need your memory to assert that your memory failed. Is there a separate memory he is talking about here? Even if that technique worked, couldn't the pattern stay the same just based off the chance that you get horizontal/vertical stripes twice in a row?

Sorry if I'm nitpicking, maybe my cs theory courses just ruin these things.