Social Security Number(s) It's one thing to have your number memorized (and you should, because it's not safe to carry your card on you), but it's another to know your spouse's. Memorizing his or her social security number is incredibly useful, as it is sometimes required for certain applications or tax forms.
License Plate Number If your car is stolen or towed, so is your proof of insurance and registration in the glove box. Being sure of your license plate number will help police locate your car much faster. If you have a bad memory, keep your old registration in your house.
Credit Card Number Think of all the times you were on the phone or Internet and needed your credit card number and its expiration date ASAP. It's much handier to memorize them than to frantically rummage through your wallet looking for your credit card.
Your Credit Score You can save your identity just by checking your credit score. By law, you are entitled to a free credit report once every twelve months. Visit annualcreditreport.com for the free report, then visit either equifax.com, experian.com, or transunion.com if you need to dispute information in your report or place a fraud alert.
Debt The majority of people don't know how much debt they have, and even if one spouse does, the other is likely not to. Count your mortgage, home equity loan, car loan, credit cards, student loans, and anything else that is owed. Calculate the balances, your minimum monthly payment, and the interest rate. Track changes each month.
Allergies Not knowing what makes your throat itch and eyes water can be annoying, but it can also be quite dangerous. The absolute last way you want to learn about your food allergies is after you've eaten the allergen. Getting a skin or blood allergy test will help you determine what allergens trigger a reaction; it could even save your life.
Another dangerous allergy is one to medication. Penicillin, sulfa drugs, and iodine are among the most common drug allergies. If you or a doctor suspect you are allergic to a particular drug -- you get hives or other reactions -- you may have a skin test done, but this doesn't always work and can actually be more dangerous. The easiest thing to do is to simply rule out the drug as treatment. In either case, keep a list of severe allergies with you at all times in case incapacitation prevents you from telling someone.
Body Mass Index Body Mass Index (BMI) is a number that uses your height and weight to determine if you have a healthy weight. Knowing your BMI can help you determine if you're at risk for health problems related to obesity, or just see where you are on the overweight/obesity scale (though standard BMI is not an accurate measure of risk for children or body builders). Some services calculate BMI against age for an even more informed judgment of your health. For a free calculation, go to nhlbisupport.com/bmi.
Cholesterol and Blood Pressure Heart disease is the number one cause of death in many Western countries, and you should know if you're at risk. High cholesterol and high blood pressure can cause a heart attack or stroke, so visit your doctor to find out where you stand.
Medical History You may have your dad's smile and your grandma's beautiful eyes, but you can inherit a lot more than their looks. Doctors say knowing your family's complete medical history will help you be more aware of hereditary diseases you might have or develop. It can be difficult to get family members to share something as personal as their medical history, but let them know they will be helping you and your family stay healthy. Ask your parents, siblings, and grandparents if they have high blood pressure, high cholesterol, heart problems, cancer, mental illness, food allergies, stroke, diabetes, asthma, or age-related illnesses. Also, find out the ages at which deceased family members died.
Organ Donor Status Decide today whether you want to be an organ donor or not. By not deciding you may put your family in a difficult position by forcing them to make that crucial decision for you. If the choice is made in advance, your family won't have to feel guilty for choosing one way or the other. Go to organdonor.gov to find out how to change your donor status.
Current Medications Some drugs don't mix well with others. Every time you go to the doctor, take a list of your current medications and the dosage so he or she can prescribe a drug that won't react negatively with the others.
Will An estimated 75 percent of Americans die without having written a will. You can create a will easily online at legalzoom.com; just make sure you and two witnesses sign it once you receive it. And most importantly, keep it in a place that family members know about. By this same token, be sure you know where your parents and loved ones keep their wills so that their wishes can be executed properly when the time comes.
Taxpayer Rights Getting the biggest tax refund possible is all about choosing the right form and knowing your rights as a taxpayer. To determine which form is best for you and to learn more about filing taxes, go to irs.gov/advocate.
Insurance Policy Details What's your deductible for a trip to the emergency room? What about if you wreck your car? Or if your basement is flooded? Knowing information like this ahead of time can help you decide what action to take in a crisis. It can also prevent delayed medical treatment, unexpected bills, and other unpleasant surprises.
Information about You on the Internet Complete strangers can learn almost anything they want about a person through the Internet -- home address, telephone number, personal interests, etc. See what information about you is available by typing your name into a search engine like Google. You'd be surprised how much is out there for the whole world to see.
Helpful and Interesting Information
Air Quality You can check your city's air quality daily at airnow.gov to see if you're at risk for breathing in harmful air pollutants. This might help you decide if you're going to go hiking or biking as a family.
Clothing Size of Family Members Who doesn't like presents? But trying to surprise loved ones with size-related gifts can be tricky. Without knowing their correct clothing sizes, you either have to ask them -- ruining the surprise -- or purchase the gift and risk the need for a return or exchange. It's also handy to know everyone's shoe size.
Your Car's Gas Mileage From recent experience, we all know gas prices can skyrocket at the drop of a hat. Find out now if you're getting your money's worth from your car. The next time you fill your gas tank, record the amount your car takes and reset the mileage tracker. When that tank runs out, record how many miles you got on the tank and divide it by the amount you put in the tank to get a tentative miles-to-gallon ratio.
IQ Intelligence quotient, or IQ, is a way of measuring intelligence through a standardized test. A person's IQ can relate to a lot of things, like health and income. Learning it can also be a fun experience. The IQ scale ranges from 0 to 200, with 50 percent of the population scoring between 89 and 111. For a free test, go to iqtest.com or highiqsociety.org.