"oh John, my dear, you don't know what love is, you have no idea what it means to love someone to the point of doing anything for the other" this is what Larita had said to her husband ,John,before leaving his life forever

John, now, no longer had a wife, he no longer had Larita, he felt lost and always thought of those words "you don't know what love is", what do they mean exactly? would he ever find someone to do crazy things for?