Roger this is very interesting, and an issue that plagues me.
My comfort zone has always been "portraits" of single objects and some still lifes (you can see my web page below). I seriously love doing that, and (IMO) am good at it. But .....
In my mind, I have beaten that theme to death, and badger myself with "Jees, Dave, not another still life!"
For several years now I have been trying to get people into my pictures. Not posed, just people doing something. But I can't get that done right, so I fall back and do another still life photo. (Maybe it's a "control" issue?)
It still excites me to do still life scenes, but I want to do new things . I just can't move into that larger world.
"Comfort" is a two edged sword.