In another life, I would be...
a) An actress - I was once told by one of my high-school humanities teachers that I'd make a good actress. She said so based on me reading a part as one of the witches in Shakespeare's Macbeth. I enjoyed being a witch. I think acting would be very fun but I've never taken a single drama course in my life, unless you want to count playwriting.
b) A counselor - In my fourth year of university I took a psychology course called "Interpersonal Helping Skills". I loved the class and got an A+ in it. I began to consider pursuing a career in counseling, but realized it would take a heck of a lot more schooling, and at that point I was pretty much burnt out and tired of writing essays. And anyway, now look who's needed (still needs?) a bunch of counseling... ahem.
c) An artist - I'm already an artist (in process), but in another life I'd be a single artist with no children. I'd rent a simple apartment (aka studio) or a tiny house in the middle of town. I wouldn't have a car. The weather would be mild all seasons of the year and I'd walk everywhere. I would paint, sketch, write, play the piano and guitar and maybe the cello.