one’s own reasons
У каждого свои причины, Виктор.
Everyone has their own reasons, Victor.
— Охота за «Красным Октябрем» (1990)
Уверен, у вас есть свои причины.
I'm sure you have your reasons.
У Тома есть на это свои причины.
Tom has his own reasons for this.
She has her own reasons.
У Тома свои причины.
Tom has his own reasons.
I have my own reasons for this.
У него свои причины там оставаться.
He has his own reasons for staying there.