Ask HN: Thinking of quitting job with no plans for the future: bad idea?

A little background (and I apologize for any vagueness, I'm a bit paranoid about coworkers that read HN): I've been a developer for about 6 years now, first and only job out of college. On paper it sounds like a great job: pay is above average, various perks, smaller firm, casual working environment, and I have a lot of autonomy. But my particular career path isn't really going anywhere anymore, and I find that over the last several months I've lost most any interest in my industry (not coding itself, but the field for which I write software for). The job itself has consequently become unsatisfying and thus emotionally and psychologically draining.

My goal is to join a startup, and go back to just plain building cool stuff. I am (or at least used to be) very ambitious, and I want to work with smart, ambitious people who want to build the next big thing. I'm just not sure if I'm qualified to be in that company right now - my skillset is so particular to the role I'm currently in I don't think I'd get very far (confirmed by some interviews I've had this year). I'd love to pick up web development again and work on projects in my free time, but it would take so much time away from the few hobbies I have that I'm pretty sure it would just make me feel worse.

So I'm thinking that maybe I should just quit, and do nothing for a while, try that whole "finding yourself" thing I never did. Maybe travel a bit, try and get some enthusiasm for life back. Everyone says not to do this without having your next job lined up, but does that apply if you're not looking for a traditional office job, if you seriously just need a break with no commitments? My big worry is that I don't figure anything out and find that a year later I'm having a very hard time finding a job again, and/or the economy is much worse.

Some important points: I have no wife/kids to support, not in a relationship, I rent, and I can afford to be unemployed for at least a year (at an acceptable level of comfort). If I leave my industry, I wouldn't bet on making it back in, certainly not at my current level because experience in my niche doesn't tend to be very transferable. I also have very few connections in the industry (sounds weird after all these years, but it's true). I've thought about grad school too, but I couldn't get more than one quality letter of recommendation at this point, so I wouldn't bet on getting into a top school.

So I'm at a loss as to how to assess this situation and figure out what's smart and what isn't. HNers seem to come from all walks of life and have collectively seen and done it all, so hopefully someone's been in this situation and has some wisdom to impart.