I'm in a position like that right now. And it is driving me crazy. Sure the pay is good. And the responsibilities are well-defined and reliable.

But the challenge and enjoyment is not there. I find myself working like crazy after hours to carve out a new career while still maintaining the income of the day job.

The balance between stressed-out and challenged can be hard to strike. But I know that for me I need to be challenged to be enjoying my work life.