grammaticality - "It's an interesting topic for me" versus "It's interesting to me": Does it really matter?

I've just caught myself out twice by writing something down as being interesting for me! This is a typical Italian mother-tongue error, but Italian is not my first language. It used to be English, but now I'm no longer sure.

And yet when I say the above phrase it sounds OK. I feel comfortable saying it, so am I right to use the preposition for in this way? If as a linguist said: "Grammar is about how people really speak, not about how they ought to speak."

Here is a link which nicely sums up the difference between interesting to me and interesting for me.

Something you do is interesting for you.

Something people do or say is interesting to you.