Trying to remember something can prevent the memory from being retrieved.
Thinking hard about something is unlikely to jog the memory
A Cambridge scientist suggests that people desperately trying to recall something are better off letting their mind focus elsewhere or relaxing in order to improve their memory.
Professor Jon Simons, the head of the Cambridge University Memory Lab, told the Rosebud podcast: "What happens when we're really really trying to remember something, is often by that very effort block the memory from being retrieved.
"And it's only when that effort that we've put in gradually subsides and we maybe think about other things or we just calm down and relax that the memory is able to be retrieved."
He added: "It is interesting how often you can puzzle and puzzle and puzzle over something and really, really try to remember it and struggle - and then the moment you think about something else, suddenly it pops into your head and that's quite a common experience."