PH
Dating someone for a long time can change how you remember information.
Researchers studied 118 people who had been dating for at least three months.
Established couples performed better on a memory task than newly paired strangers when they were allowed to rely on their naturally developed memory structure.
This relates to what's called transactive memory.
Instead of both partners remembering everything, each person can learn what kinds of information the other is good at remembering.
Eventually, “I don't remember, but my partner will” can become part of the couple's memory system.
Your partner can essentially become one of the places your brain expects information to be stored.
© Journal of Personality and Social Psychology (1991)