Changing career paths has been a feature of roleplaying games ever since the days of Advanced Dungeons & Dragons, with its mechanic for dual-classing. Essentially, you could begin your adventuring career as, say, a fighter, and then after gaining a few levels you could - if you had the requisite ability scores - switch to being a magic-user, or a thief, or whatever. The benefit is that you have the skills you learnt before switching, plus you pick up a bunch of new skills related to your newfound profession. The drawback is that you have to start again from scratch, learning the new skills at a low level.
Anyway, you can extend this sort of thing to any game you are playing. If someone is sick of being a pilot or a journalist or whatever, they don't need to retire and bring in a new character. You can simply have them switch career paths and start learning something new. It's realistic, and you get to muck about with someone at clueless newbie level in your current adventuring group!
Chewbacca: I have news too. I started my first teaching job.
Leia: Awesome! Congratulations, Ben.
R2-D2: Quite the U-turn... medicine to music teaching.
Chewbacca: Well, you kinda did the same thing from IT.
R2-D2: Exactly. Takes guts to change your career path. But it can work out well.
Chewbacca: Oh. Thanks.
C-3PO: I used to do that all the time! Top tip: Borrow the gear before you buy it, unless you want three closets full of junk.
Chewbacca: Thanks, but I think I can manage, Sally.
C-3PO: Suit yourself. You have plenty of empty closets at your place anyway.
C-3PO: Actually, can I bring some stuff over?