Enough people have asked me this question lately, I think it's worth an in-depth explanation.
Why the West Coast?
meerkat299 is from northern CA and has never felt at home out here
Both of us like being near ocean and Real Mountains
Cities are newer and better designed
More environmentally conscious (in general)
Why Seattle in particular?
I think I would have trouble dealing with the drought conditions of northern CA
ezzie00 and alegria_a are there
we both really like the feel of the city (more on that below)
climate is mild and consistent - none of this dithering winter/summer crap.
evergreens! that means no allergies!
homeschooling- and libertarian-friendly
close to Canada in case something goes (more) horribly wrong with this country
So what is it about Seattle?
We visited there in August with Seattle already high on our list of prospective places to end up. But even without that pre-formed bias, I just loved the city. I spent a week walking around downtown trying to pin down what it was. Some of the factors were the geographical/climate type features I mentioned above - but the most remarkable was the unavoidable conviction that the people there are there because they want to be; they're doing what they want to do; in a much higher proportion than you will find in most places.
shoebox_bird mentioned at the time that the city felt to her a lot like Pittsburgh - to me it felt a lot like a revved-up Santa Cruz or a newer San Francisco. It does have a lot of the nicer features of Pittsburgh - eclectic architecture scattered over many eras; three-dimensional; the climate averages out to be similar (Pittsburgh just has a *much* larger standard deviation). And like northern CA, it's liberal (in the non-political sense) and easygoing, but you have the overlying intense focus of people seeking and achieving their life's work.
There seems to be a big independent arts/music scene; there are parks and national forests everywhere, and two other large cities within a reasonable drive. Lots of large independent bookstores. The roads aren't in magnificent shape but at least the layout is designed pretty well.
Why do you feel you won't be happy until you move there?
We do know that where you live does not solve all your problems, and we aren't expecting it to. But just as having a messy house drains on you day after day and makes it more difficult to enjoy the things that are good, so does living in a geographical environment that doesn't suit you. I imagine living in a place where I look outside and see green mountains every day - where the air is cool and moist, and my sinuses don't constantly fight to stay functional. I imagine living in a place where I don't wake up with itchy eyes and throat half the year, where I don't go through a box of kleenex a week. I imagine having my immune system not be constantly off-balance because it never knows what temperature it's going to be tomorrow. These things will make a significant difference in my quality of life.
Also, I am a control freak in some (ok, most) regards. Even if I liked it okay here, everything in me rebels against staying because it's the path of least resistance. I want to *choose* my environment, and if I stayed here or moved back to Pittsburgh, I would never be sure that it wasn't simply because it was the straightforward, easy path.