I forgot to ask if I could be a Xenobiologist.  I'll have a bit of medical experience, but not enough that it would have made sense having him as a nurse or doctor on Voyager.  He just did some minor treatments on a cargo ship he worked on, then was a medic for Chakotay's ship for a few months.  Mostly that was because he knew more about alien lifeforms and biology than the rest of the crew in both cases.