I can hear my main character's voice better. She's more alive. It's so different! Such a great exercise! It is not merely changing the she to I, the was to is. Check out the one sentence I was able to work on this morning:
The ride to the airport rushed by in a blur. Memories of things said tugging at her mind, things that she would rather not think about.
The ride to the airport is a blur as memories tug at the corners of my mind. Self analysis has never been my friend, so I try to focus on my environment, even though we have left Manhattan far behind. I wish that we had stopped in Harlem to buy a mango-on-a-stick or at least some honey-roasted peanuts, but how could I have done that with a camera in my face?
It's so immediate, and works better for the situation. I am hearing her thoughts. And dialogue is so different too - there's no he said, she said.
I'm interested in this because I always write in third-person past tense. It's just the way I've always written, and it doesn't even feel like a lack of freedom, although Katonah clearly feels like the switch has freed her. Sometimes that happens, by the way-- you make a change in what you're doing and suddenly feel unstopped.
Still, maybe someday I'll try, say, an Alex Van Helsing first-person book, the way Patricia Cornwell goes back and forth from book to book.