*nod* I came across this idea in the context of a study that was looking at drug experiences - interviewing people while they were under the influence and then again after they'd come down - which found that people described a much happier experience in the second interview than in the first one. In other words, the drug was making their memories happier, not their moment-to-moment experience. I forget which specific drug it was, though. As you say, it's changed the way I think about happiness quite a lot. I note also that diagnostic tests like the Burns Depression Checklist look for remembered rather than moment-to-moment states of mind in the way they're administered - people aren't diagnosed by being given sheets to keep with them and track how many times they actually feel inadequate, tired, worried about their health etc, but by asking them at the end of a given period (often a week) how inadequate, tired or worried they remember feeling during it. So depression isn't necessarily about what you feel moment-to-moment, but about what lasting impression it makes on you. Which in turn reminds me that my yoga teachers talk a lot about learning not to allow negative experiences to make an impression.