Once we achieve immortality the way we work would be very different. Most likely we would work in one career for a certain period of time then we would take a break kinda like a short retirement and then possibly go to college again and do a totally different career and so on and so forth. When it comes to the likelihood of achieving immortality i'm pretty sure we have a VERY good chance and likely even in the not too distant future. You should check out some of the current research going on in gerontology. I also suggest that you check out my article on the subject here:
https://steemit.com/sciencefiction/@digitalcosmos555/futurtopia-2-living-forever