Colonial outposts

I saw this post about living on the ocean floor, and it occurred to me that the idea completely icks me out. The idea of colonies in space is awesome. I would jump at the chance to live on the moon, or even in a tin can colony. Even if it meant I'd see the same 99 people for the rest of my life and eat nothing but algae and spend my days doing drudgery in the pee-to-water recycler. But transfer all that to the bottom of the ocean, and I can't run (swim?) away fast enough. Maybe it's something about the pressure of all that water. Maybe it's the view outside the porthole - not that there would be one, but if there was it would only show blackness and depraved fish instead of the stars. The world, in practice, would have the same circumference, but I wouldn't be able to see beyond it. Maybe it's just my fear of blindness.