When you read a novel, discovering what the occupation of the main characters helps define the character in your mind.
Janie Hannagan, the main character of WAKE, works in a nursing home, and that is simply the best darn job for her.
When you WRITE a novel, having worked in a variety of places helps make giving occupations to your characters a bit easier. The more experience an author has in a variety of occupations, the more options the author has. This is not to say that an author can't research and create an unfamiliar job for a character -- it's just easier if there is some life experience one can draw upon.
I never worked in a nursing home.
However, my mother did. She was a beautician, and one day a week, she would set up shop in the nursing home on 40th Street and do hair. My sister and I went with her sometimes. We got to know the residents there. Spent some time in the game room hanging out with the old folks and playing games while The Price Is Right blared full volume in the background.
It was a learning experience -- one I never expected I'd write about thirty years later. To this day, I enjoy visiting residents in nursing homes. There can be a lot of joy there.