I think that, regarding the paradox of "working" post FIRE, the situation goes something like this:
Post FIRE, we end up with a lot of time to pursue our passions. When we pursue these passions with all the time and dedication we think they deserve, you actually have to try to NOT achieve a level of proficiency where people would pay you to use that skill.
TR wrote about the "Strenuous Life" and believed that, when faced with two paths, one should choose the more difficult because it was the most rewarding. I think that Mustachians share this idea and trend with him (maybe it's because we are overwhelming INTJs).
To me, when we work towards FIRE, we are choosing the more difficult path. The obstacles are many, but, when we get there the reward is so much more than the standard "work til 65, then die."
Forummm:
As to your dilemma, a few questions (rhetorical and introspective):
Would this change be something that brought your net happiness up, even knowing that you would sacrifice FIRE for longer?
Could the job you wish to pursue be something you could due post-FIRE? (For example, my degree is in teaching and that is my passion, but I work a corporate job till I have FU money then I will most likely teach because then the money doesn't matter)
Does working 40 hours a week at a job that you find okay really suck that bad? I would do some nasty stuff if it let me FIRE 5 years earlier than normal.
These are the questions I would wrestle with myself.
Thanks,
Hall11235