To answer the original question, apart from the specific grace of God, pure love is not possible after puberty. It is probably not possible before puberty either, but hormones really mess it up

At best we have mixed motives.
The highest form of love is "focused, persevering, altruistic benevolence." Affection, Passion, Friendship, and Compassion are all "messengers" or "angels" of such love. If they remain truly focused and persevering in altruistic benevolence, they become powerful messengers of True Love. If they become wrapped around self-will and self-indulgence, they become fierce demons. Affection becomes Abuse. Passion becomes Lust. Friendship becomes Cliquishness. Compassion becomes Co-Dependent Enabling.
The stronger the raw desire/angel for affection, passion, friendship, or compassion, the fiercer the demon it becomes if it falls away from True Love/ Focused Persevering Altruistic Benevolence.
"Lucifer" was perhaps the highest Messenger/Angel. He became the fiercest demon when he walked away from True Love and chose Self-Will.