It is just a fact of human life that people have the capacity for good in them somewhere -- even if it is undeveloped. It goes with being created in the image of God. It is also a fact of human life that this capacity for good is often undeveloped not only in others but in ourselves as well -- and that pride, jealousy, a bad history, or a competitive nature can make us more likely to find things to criticize than things to praise. We tend to find what we're looking for.
Love has the impulse to look for the good. It is like a precious-metal detector that finds what is beautiful in the other person, even if it is buried deep. When it finds that gold, it uncovers it and lifts it up. I'm reminded of one of my grandmothers, who was always rehearsing stories in her husband's praise. In the way that a jeweler takes all kinds of study and applies it to how to cut a gem, how to show it to best advantage so that it catches as much light as human skill can arrange -- so my grandmother would take just that much care with the "jewel" events of my grandfather's life. I wonder if she was polishing as she was retelling. I don't recall my grandfather ever blowing his own horn; considering my grandmother, there was hardly any need. She could communicate that my grandfather was a treasure in a way that made clear she thought she was quite the lucky woman as well. I doubt my grandfather -- or any of his friends -- ever harbored any doubts about her devotion. My grandmother was a master jeweler in that kind of craft. May I be that, starting with my children.
I think to some extent we're all the treasure-hunters and jewelers in each others' lives. It takes insight to see what is good. It takes determination to keep looking. It takes wisdom and skill to present someone else's life in a way that it shines. Love does that.
More than that, love is the alchemy that changes the baser matter into gold. It adds that hope to the other person, that desire to develop their own capacity for love and kindness, for wisdom and understanding. It is in our hearts' desire not only to be treasured, but to deserve it. In this way love shows itself nearly the opposite of flattery: where flattery plies someone with undeserved praise to manipulate and deceive, love gives every bit of deserved praise to build up the other person.