I think it's an excellent idea! It will enable you not only to acquire a fund of stories which may indeed be compiled into a book one day, but will help you to hone your writing skills!
Think of the "vet" books by James Herriott, and the "Doctor" series by, I think it was Richard Gordon...I think it's high time a talented nurse author jumped on the bandwagon.
Just remember the privacy laws, which I'm sure I don't even have to mention, and go and get yourself a nice thick hard cover book to jot down your stories while they're fresh in your memory; if you are planning on typing it on your pc, always back up a copy, or print what you've typed-there's nothing more frustrating than compiling something and have your HDD crash!
I hope you have lots of fun and make lots of money