There's a lid for every pot

My Grandma Evelyn would have loved this. She was a serious student of humanity; even though she was functionally illiterate with a third grade education, she was a keen judge of human character and loved to study art and nature. Whenever she'd see an unlikely coupling, her go-to comment, brief and pithy, was "See? There's a lid for every pot." I still find myself saying this when I see two misfits find each other.