Time.

Each has to enter the nest made by the other imperfect bird.

Patience is not sitting and waiting, it is foreseeing.

It is looking at the thorn and seeing the rose,
Looking at the night and seeing the day.
Lovers are patient and know
That the moon needs time to become full.

This is what love does and continues to do.
It tastes like honey to adults and milk to children.

Rumi