Episodic memory is sometimes called autobiographical memory (though certain neuroscientists consider them to be different phenomena). This refers to the experiential remembrance of one’s own life: what one had for breakfast, one’s first day at school, and so on.
Forgetfulness is fundamental to the human cognitive system. Without it, all manner of information processing tasks would grind to a halt. What would happen if your brain malfunctioned and lost its ability to forget autobiographical memory? You’d never forget where you left your keys. A good thing or a bad thing?
Jill Price (known as AJ in the literature) has hyperthymestic syndrome, and she was recently interviewed for a local NPR station in the United States.
[She] has a memory like few others in the world. She’s 42 years old, and she remembers everything.
Quite an extraordinary condition. If you’re interested in these things, I’d recommend Alexander Luria’s wonderful monograph on a Russian man called Solomon Shereshevskii, who appeared to have an unlimited memory thanks, in part, to his synaesthesia.