Today’s Wonder of the Day was inspired by Angel . Angel Wonders, “Why do some people have photographic memory?” Thanks for WONDERing with us, Angel !

Do you like tests? If you're like most kids, the answer is probably a resounding “No!" Tests can be a lot of work, especially in subjects like history that have a ton of facts to remember.

Sometimes you might wish you had a better memory. Have you ever gotten down to the last couple of questions on a test, but you just can't seem to remember the answer? At these times, you probably wish you could see the pages of your textbook like a photograph in your memory.

Do you know someone who has a really good memory? Some people are gifted in special ways when it comes to exceptional memory. Some people even claim to have a photographic memory. This means they can recall things they've seen or read with almost-perfect precision, even down to the smallest of details.

Photographic memory is the common name for eidetic memory. The word “eidetic" comes from the Greek word that means “seen." Eidetic memory is actually broader than photographic memory.

Photographic memory often refers to precise recall of mainly visual images. Eidetic memory, on the other hand, refers to precise recall that can involve details gained from the other senses, such as hearing, feeling, taste, and smell.

One example of eidetic memory is the ability to study an image for about 30 seconds and keep an almost-perfect photographic memory of that image in the mind after it's removed. People who can do this — sometimes called eidetickers — claim that they can “see" the image in their minds as if it was still right before their eyes.

True eidetic memory is very rare. Some scientists have observed that individuals with autism or autism spectrum disorders, such as Asperger syndrome, may occasionally exhibit exceptional memory that resembles eidetic or photographic memory.

For the most part, though, extraordinary memory events are just that — extraordinary, but not necessarily up to the level of eidetic or photographic memory. In fact, most claims of true eidetic or photographic memory are merely word-of-mouth reports that haven't been proven scientifically.

Many people have developed extraordinary memories over time by using a variety of skills and learning techniques. For example, a Japanese engineer — Akira Haraguchi — has memorized the mathematical constant pi to its first 100,000 decimal places. But does he have a photographic memory? Nope! He's just good with numbers!

Wonder What's Next?

Tomorrow’s Wonder of the Day might make you really, really hungry!