Childhood memories might best be kept in a photo album, not in your mind. Turns out, storing old memories can make you forget an important appointment or what you needed to buy at the store today.

Too many long-term memories make it hard to properly filter new information and process short-term memories, according to a study last month in the Proceedings of the National Academy of Sciences.

"In our world, we are constantly bombarded by new information so we are constantly filtering, and if we did not do this, we would be overwhelmed," said study team member Gaël Malleret of Columbia University Medical Center.

The new research indicates that those with better working memory may have fewer new neurons being developed in their hippocampus—a region of the brain involved in formation of memories. This "helps them forget old and useless information sooner and enables them to take in new information faster,” Malleret said.