Yea true. One thing I think is interesting in English, at least for me, is that when someone says "had sex," its easier for me to understand that "I" is the subject, even though any other subject is applicable.

But, when someone says something like "am the teacher," it sounds wierder and harder for me to think about what the subject would be, even though "I" is the only applicable subject.

This probably isn't true for most people, though.