In fact that is the struggle that most Americans - As rich as this country is, most Americans are very limited in their interaction with the world, unless the world comes to us in a very shocking way.
It wasn't a problem for me drawing humans although I had originally come to the studio with the idea that what I had to offer them was my knowledge in the drawing of animals.
There are plenty of recommendations on how to get out of trouble cheaply and fast. Most of them come down to this: Deny your responsibility.