Do you sometimes have not an opinion on a subject?

I was watching a television show on immigrants that moved to Holland to be with their loved ones.
One guy was from Gambia and he fitted in perfectly.
His girlfriend said that she liked the fact that he regularly has no opinion on things she worded it in a way that it sounded not as if he was ignorant about certain subjects, but he just didn’t think about everything, and/or didn’t think those subjects were of interests to him.
That made me think that a lot of people do have opinions on (almost) everything at least, I do (on many subjects).
Are there subjects that you don’t have opinions on?
If so, why?
Not knowledgeable (enough)?
Not interested?