I think love in all its shapes and forms, as love between partners, friends, parents, and children, love for what we do and create, love for nature, love for animals, love for our planet...it is what keeps us going. It is a part of the quintessence-the 5th element. In quantum physics, if some particles and actions are not observed, they don't exist. If love is an illusion, it is a group illusion we all experience on regular bases, and it is something we all observe, so it has to exist.