Just curious -- in a typical 1 hour cycling class, how much time is typical to be in the saddle, and how much out?

I went to a class with a different instructor last night, and she spent easily 45 out of the 60 minutes out of the saddle. That seemed like a lot to me (and, I couldn't do it).

Particularly you instructors out there --is that typical? Is there a set guideline ya'll are taught? Am I just a wimp?

I figured in real riding conditions I would never be standing for 20 minutes straight, and that's what I told myself when I sat my butt down. But I am curious what others think of this.