#16 - Weakness
Vincent watched her stare down the three-headed monster and wondered where she found the strength to attack her own father, and just how he had gotten so weak.
#17 - Tears
He could never decide which was worse, after Aeris died: her tears (how he wished to wipe them away), or her laughter (how he wished to pull her close and silence her).
#18 - Speed
Vincent always wondered where Yuffie had learned to run so fast-- but even more, he never understood why she never ran away from him.
#19 - Wind
When they defeat Sephiroth, her joy is fleeting: there and gone again, like a breeze, and he wonders what would make her smiles real.
#20 - Freedom
Vincent asked her why, once; she laughed at him and said: "Because I can." He never asked again.