Who said "I've loved once; it was enough to teach me everything."?

This quote is attributed to Agatha Harkness.

I've loved once; it was enough to teach me everything. - Agatha Harkness

"I've loved once; it was enough to teach me everything."

Agatha Harkness Love

"Well, hello, dearie."

"The real question is, what are you willing to do to keep what you love?"

"Power isn't given, it's taken."

"I'm not a witch. Well, not a traditional one anyway."

"I love my wife, but sometimes she drives me crazy."

"Love conquers all obstacles."

"Love is patient, love is kind."

"I'm not stupid, I'm just in love!"