The next time you fumble the facts when you’re reminiscing, psychologists have some comforting words: It doesn’t matter.

Inaccurate memories can even be good for you, according to several studies in the past year. They are often just as helpful as accurate memories in shaping people’s sense of identity and aiding goal-setting.

A middle-aged lawyer cherished a vivid boyhood memory of his father comforting him while his mother was in the hospital giving birth to a younger brother, says Martin Conway, head of the psychology department at City University London. The lawyer recalled his father distracting and entertaining him by talking about the landing of a man on the moon. He saw it as a sign that even with a baby brother on the way, his dad still loved and valued him, Dr. Conway says.

Only decades later did the attorney see that his recollection had to be wrong: His brother was born in 1968, a year before the first moon landing, says Dr. Conway, author of more than 150 studies on memory. “I’ve had this cherished memory for 30 years that I thought was true, but as I listened I suddenly realized it couldn’t be,” the attorney told Dr. Conway.

He had probably patched together details from separate events to form a single memory, Dr. Conway says. The memory was on-target in a deeper sense: “The fact that he was still loved was a truth to him, an important truth,” shoring up his sense of identity, Dr. Conway says. “It’s not so important that a memory be accurate. It’s more important that it helps us define ourselves.”

Dr. Conway’s work builds on a shift in psychologists’ understanding of long-term memories about our lives, or autobiographical memory. A growing number of researchers say memories are not just a storehouse for facts but also a creative blend of fact and fiction that helps people tell meaningful stories about their lives, set goals and envision the future in a realistic way.

It is commonly believed that storing a memory is like making a video, but long-term memories are never literal replays. They’re mental constructions of facts, inferences and imagined details that people patch together after the fact.

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