Like many authors, I've held several jobs: telemarketer, receptionist, secretary, bartender, artist model, security guard, substitute teacher, server, and probably a couple more I don't remember. But I wanted to be an author since I was in middle school, when I bought a blue notebook and penned my first novella.
I also wanted to be a private investigator growing up, as well as a doctor and pharmacist. My mother was a nurse's aid and I read her medical books. Sadly, chemistry proved my bete noire. I suppose I would do better now, given my life situation is less stressful than in the past. Suffice it to say, though, we all have our educational strengths. Mine is English, while my husband's is science and math. Our daughter took after him. It all balances out.
Over the recent years, I've sometimes wished I'd gone into forensic science, either forensic pathology or computer forensics. That, or become a homicide detective. The reason? To help solve murders and other crimes. Crime scene investigation has fascinated me for years, as my bookshelf can attest.
I've written a couple of homicide detective characters. Been playing around with creating a private investigator and writing a series of tongue-in-cheek novellas. Other characters I've been working on are NTSB investigators, a US Postal Inspector, and a former Secret Service agent. Not an exhaustive list, to be sure. And yes, there are a couple of characters who work as doctors.
Like actors can play various roles, so too can authors live vicariously through their characters. Even better if the author has similar experiences for real world comparison, but for those who don't, creating a fictional world is one alternative.