A long time ago, Remides wanted to be like her fellow kinsmen and throw herself into the Phoenix Holy Fire to end the torture that the years had brought her.
500 years was the limit most High Elves had set for themselves, and this limit referred to the time spent on the concept of draining emotions.
Emotion was consumable. It used beautiful memories as a carrier to slowly accumulate in the first half of one's life before being slowly worn down, depleted, and forgotten in the days to come.
Memories with emotions were fresh, but perhaps it took more effort to recall them. To reduce the burden of memories on her soul, those fresh memories began to fade after a few centuries. Finally, only simple logic remained.