For years, it's been thought that long-term memory holds much less detail about things we remember than short-term memory. However, new research from MIT suggests that longterm memories may not be that fuzzy, but are just harder to find. From Scientific American:
If our memories aren’t all that fuzzy, then why do we often forget the details of things we want to remember? One explanation is that, although the brain contains detailed representations of lots of different events and objects, we can’t always find that information when we want it. As this study reveals, if we’re shown an object, we can often be very accurate and precise at being able to say whether we’ve seen it before. If we’re in a toy store and trying to remember what it was that our son wanted for his birthday, however, we need to be able to voluntarily search our memory for the right answer–without being prompted by a visual reminder. It seems that it is this voluntary searching mechanism that’s prone to interference and forgetfulness.Why Do We Forget Things?