Final answer:
Source misattribution is the type of memory failure that occurs when you think you remember an event that was told to you by someone else.
Step-by-step explanation:
The type of memory failure that occurs when you think you remember an event that was actually told to you by someone else is called source misattribution. Source misattribution refers to attributing a memory or idea to the wrong source of information. It occurs when you mistakenly believe that the source of a memory is different from its actual origin. For example, if someone tells you a story about an event they experienced, and you later recall that event as if you personally experienced it, you would be experiencing source misattribution.
Thus when you think you remember an event that was actually told to you by someone else, it is a form of memory failure known as source amnesia or source misattribution. This can lead to confusion about the origin of memories and may cause you to incorrectly attribute a memory to your own personal experience.