I've mentioned this in brief on a couple othe threads, but the long version seems warranted here:
I've spent the last 7 years gaining education in my field of choice (my passion, if you will). That field is theology, and it more or less qualifies me to do one of two things: Serve as clergy, or teach theology. I have been a clergyperson in my denomination since 2007, putting in full-time hours since 2008, and in that time I have received less than $20,000 for doing so. That's less than $20,000 total, not per year, and over 90% of that came in a one year period. Since May 2010, I have been a full time staff member of my current church for free.
I love it. I could not be happier than when I'm doing my church work. Some day, I hope that some combination of work in the parish, and in a school (I want to do that "teach theology" thing, as well), will pay enough that I can focus 100% of my professional attention on church work. But if that never happens, I'm okay with it.
Contrast that with my paying job. I'm currently working as a supervisor at America's favorite coffee shop. You may know it as the company most frequently referenced by financial talking heads who talk about saving by cutting out small expenses, like a daily latte. Other than the fact that I'm an avid coffee drinker, this job really has none of the qualities I would seek in a place of employment. There is no down time, which sucks for an introvert. There is no interaction on anything but the most superficial of levels. It's a culture where the prevailing wisdom is to bend over backward to make others happy. And it's a place where I'm constantly reminded of how stupid people are with their money. Basically, it has everything I wouldn't look for in a job, and more.
My point here, though, is that you don't have to choose between the thing that's going to pay the bills, and the thing that you'll love (unless the thing that's going to pay the bills is being a doctor, and the thing you love is being a lawyer). And before you toss out a string of "yeah, but..."s, I'm married, with a child, and a full-time student. So yes, there's time in the day for both if you manage your time well. Just be willing to compartmentalize- "I'm doing X because it's the best financial move, but I'm also doing Y because I love it." Focus on the long-term rewards of doing X, and the immediate rewards of doing Y, and remind yourself that you only have to do X until you're FI, which will give you even more time and resources to do Y. Ideally, X and Y will be the same thing, but if they're not, it doesn't mean you have to choose between them.