我也來湊一腳~~! 不知道對不對喔 看看就好
(1)為什麼喔，當你是他的時候你就能理解了。
用倒裝語氣會強一點:
Not until you were he can't you realize the reason why.

(2)當你能理解他為什麼這麼做的時候，這了解才剛開始。
Understanding just begins while you begin understanding him.