Transient global amnesia (TGA) is a rare condition where someone experiences a sudden and short-lived period of short-term memory loss. During a period of TGA, a person may know who you are and be able to tell you their name, but at the same time not know where they are or what you said 10 seconds ago. That said, TGA is not serious and people don't generally experience complications. Nonetheless, it can be very scary, both to experience and to witness.
Intrigued? Check out this gallery to learn more.