I know of someone who, due to circumstances beyond their control, was made to forget ever meeting their closest friend, and the experiences they'd shared together.

Later, when they were reunited as two members in a much larger group, they still singled each other out and returned to being close, despite never remembering their previous time together.

For whatever reason...it's as though those two people were drawn to each other by the weight of their past experiences, even though consciously they'd forgotten them.