Transient global amnesia is a sudden, temporary episode of memory loss that can't be attributed to a more common neurological condition, such as epilepsy or stroke. During an episode of transient global amnesia, your recall of recent events simply vanishes, so you can't remember where you are or how you got there. In addition, you may not remember anything about what's happening in the here and now.
Consequently, you may keep repeating the same questions because you don't remember the answers you've just been given. You may also draw a blank when asked to remember things that happened a day, a month or even a year ago. The incidence has been estimated between 3.4 and 6.8 per 100,000 per annum.