We've moved numerous times in our lives, and it's always taken at least a year to become comfortable with a new location and environment. Where's the grocery store? What's the best way to get from A to B?
The reality is, experience helps with pretty much everything. This is a lesson that is perpetually forgotten, especially by me.
There is so much stress with something new: a new route to get somewhere, a new place to find, a new class to teach. I'm reminded of this as I teach one class that I've taught twice before, and a class that is brand new to me. It's a bit like reading a book for the first time; only by going through a class once does one get a feel for the course material as a whole, its shape, tempo, and emphases.
A new textbook, a new course, a new classroom--these are all sources of stress, as well as ambiguity. There's no way to tackle the problem except for gain the experience you need, which requires patience and a generous helping of forgiveness. After several semesters, the material becomes comfortable, clear, and develops its natural tempo, but until then you're in the wilderness. Reading the textbook through multiple times won't give you the same perspective as teaching the class, week in and week out, for 15 weeks, and doing it again and again for several semesters. Being an expert in a field doesn't mean you can effectively teach the class, especially if you've never taught it before. Experience helps.