Design of Everyday Things [39]
THE CONSPIRACY AGAINST MEMORY
Most of us will not get our heads cut off if we fail to remember a secret code, but it can still be very hard to do. It is one thing to have to memorize one or two secrets: a combination, or a password, or the secret to opening the door. But when the number of secret codes gets too large, memory fails. There seems to be a conspiracy, one calculated to destroy our sanity by overloading our memory. Consider what we are asked to remember in our “convenient” world. A simple search through my own wallet and papers reveals the following things.• Postal codes ranging in the United States from the “short form” of five digits to the “long form” of nine. Human short-term memory can comfortably retain only a five- to seven-digit number, yet here I am asked to use nine. I need to know the code for where I live, the code for where I work, the codes for my parents and for my children, the codes for my friends, and the codes for anyone with whom I correspond regularly. American codes, such as 92014- 6207; British codes, such as WC1N 3BG; Canadian codes, such as M6P2V8. All for the sake of the machinery, and despite the fact that addresses are perfectly sensible and normally unambiguous. But machines have trouble with addresses, whereas they can deal with simple postal codes.
• Telephone numbers, sometimes with area codes and extensions. A seven-digit number becomes ten when the area code is added, and then fourteen when there is a four-digit extension. International codes, with country code and city code, add more digits. How many telephone numbers must I know? More than I wish to contemplate. All my personal contacts. Numbers for information, time, and weather; the special number for emergencies. And I mustn’t forget to dial 9 (or, in some cases, 8) so that the call will go outside the institution or company.
• Access numbers for telephone budget cards, so that when I make a long distance call from my university, I can cause the correct account to pay the bill: a five-digit number for each account (and I have four of them). Don’t show these to anyone, I am warned. Keep them hidden in a secret place.
• Access numbers for telephone credit cards, so when I travel I can have the bill automatically put on my home telephone number. The codes consist of my home telephone number plus four secret digits. The secret digits aren’t even printed on the card: memorize and destroy. But I have six of them (two home phone accounts and four different university phone accounts). If I want to dial a long distance number from a hotel using one of my telephone credit cards, I must dial as many as thirty-six digits.
• Passwords or numbers for bank automatic teller machines, those clever machines that let you put in a card, type in your secret password, and get money. Two bank accounts, two secret passwords. Don’t write them down, a thief might see them. Memorize. Memorize.
• Secret passwords for my computer accounts: can’t let people steal my valuable data, or perhaps change their course grades, or peek at the examination questions. Make the password at least six characters long, we are told. And no words—words are too easy for someone to discover—make it nonsense. (I cheat and make all my computer accounts use the same password.)
• Driver’s license number. When I lived briefly in Texas I couldn’t do anything without my driver’s license number: not pay for food at the supermarket, not pay the telephone bill, not even open up a bank account. That was one letter, seven digits. Other states have longer numbers.
• Social security numbers for me, my wife, and my children. Nine digits each.
• Passport numbers, again for my whole family.
• My employee number.
• License plate numbers for our cars.
• Birthdays.
• Ages.
• Clothing sizes.
• Addresses.
• Credit card numbers.
• Bah and humbug.
So many of these numbers and codes must be kept secret. Apparently, thieves are everywhere, just waiting for me to write down