I've been pondering the strange phenomenon of being happy without realising you are happy; or more to the point, of realising only retrospectively that a period of your life -- perhaps a period during which, at the time, you were aware only of busyness and low-level anxiety and tiredness (let's say: to do with kids and your job and the like) -- was actually the happiest of your life. How can that be? I mean, how can a person not know they're happy? Yet it strikes me as a very common phenomenon. (I'm reminded, not for the first time on this blog, of the line from Blade Runner that works as a superbly profound gloss on human nature itself, 'how can it not know what it is?')
There's an SF story about this, by I-can't-remember-whom, that I read in the Penguin Science Fiction Omnibus volume. I can't remember the title of the story either, and don't have the volume to hand.