It was natural for [him,her, you, them, us, me].
It was very natural for you.
It was very natural for me.
It was confusing for me.
It was difficult for me.
It was hard for me.
It was devastating for me.
It was hell for me.
It was bad for me.
It was fantastic for me.
It was easy for me.
It was easier for me.
It was good for me.
It was fun for me.
It was positive for me.
It was great for me.
It was better for me.
[It,The gift] was purely for me.
[It,The gift] was purely for my wife and not for me.
It was deep for me.
-flexibility-
Swimming was very natural for her.
Driving a bus was very natural for the bus driver.
[The task, It] was very hard for me.