I got it, retrogradedwithwind. 爸爸的笑 'Father`s smile' / 爸爸笑 'Father smiles' and 小明的胜利 'Xiaoming`s victory' / 小明胜利 'Xiaoming has won'. But I didn`t seem to understand 我之反也 vs 我反也, is it 'This is my food' vs 'I struggle!'?的, i.e. 之 in classical Chinese, has a function that is to 取消句子独立性 (to cancel the dependence of a sentence).
他的回复 vs 他回复
The former is a phrase whereas the latter is a sentence (though it's a wired sentence)
爸爸的笑 vs 爸爸笑
小明的胜利 vs 小明胜利
我之反也 vs 我反也