Who Can Perfectly Keep God's Commandments

Pastor walks his children through Westminster Shorter Catechism question 82—especially explaining and applying how Adam could have kept God's commandments but didn't, the last Adam did perfectly keep them in His people's stead, and the last Adam's people genuinely but imperfectly keep them now, and will perfectly keep them forever.
Q82. Is any man able perfectly to keep the commandments of God? No mere man since the fall is able in this life perfectly to keep the commandments of God, but doth daily break them in thought, word and deed.