In reply to Murcantile:
Interesting question. I guess you have to decide at some point what your values are and what kind of future is appealing. Or maybe you don't, you could go with the flow...but I would suggest that a bit of self-analysis is useful.
When I found myself in this situation, it was quite easy to decide that doing a job my heart wasn't in, climbing the ladder was a completely pointless way to live. For me, wife and kids don't enter the equation, and I have no interest in getting a bigger house or a posh car or anything that requires earning a lot. So what was I even working for? The future did not make sense.
I've retrained to do something much more satisfying and flexible so I can take time off, still earn what I need (or a lot more I suppose, if I was prepared to put the work in), change location when I want etc. The future is now quite flexible and if I don't like the way things are I can change them at will. For me, this has transformed my situation from one of staring into the abyss to feeling a lot more relaxed. I can, really, do what I want (within reason) and live by my own priorities - and they're not in line with what someone of my age and whatnot is expected to do.
I guess the thing is, if you're going to choose an inflexible, committing path (kids and job to support them) then you need to be pretty sure that that's what you actually want. If you want flexibility and an open future, then set yourself up for that. But I reckon you've got a good few years to decide!
Go climbing for a bit, see who you meet in the next few years, and take it from there?