For most of my life, stress happened when I had to do something I didn't want to do, or something bad happened to someone I love. Recently I've encountered a type new to me: being so passionately excited about work that I want to do *everything* and can't ever fully switch off.
I've had exciting jobs before; I've done work I enjoy for most of my career. I've been very lucky. Something's changed, though—probably in me. Partly I just feel perpetually under-qualified, a ditzy generalist in a sea of brilliant domain experts. But that's exciting, too.