"If everything wears off, why bother with anything?"

At this point the argument can tip into something bleak, and I want to stop it before it does. If the season always ends and the hum always comes back, then it seems to follow that nothing you do matters, and you might as well stay where you are and stop wanting things. That isn't what the research says, and the way it isn't is important.

Richard Lucas summarised the panel studies in 2007 under a title that includes the phrase "set-point model", and his conclusion was that adaptation isn't inevitable. Some events are associated with lasting changes in how people feel about their lives, years later, with no return to where they were. His list was divorce, the death of a spouse, unemployment and disability. The earlier unemployment study he did with Clark, Georgellis and Diener, in the same German panel as the marriage study, found that people hit by unemployment reacted strongly, shifted back partway, and on average never got all the way back, even after they'd found work again. A second spell of unemployment hit them just as hard as the first. Nobody got used to it.

Notice what's on that list. The events that change people for good are mostly losses. Divorce, bereavement, losing work, losing health. The gains, the wedding, the new job, the first child, are the ones that tend to wear off. It's not a perfect split, and Lucas is clear that people differ a great deal in how much they adapt to anything. But as a rough shape it's this. Bad things can move your level down and keep it there. Good things lift you for a season and let you back down.

That's not a reason to do nothing. It's a reason to point your effort differently. The next thing is an attempt to raise the level by acquiring something, and the research says that attempt mostly returns you to where you were. Protecting against the losses, the job that's actually damaging you, the marriage that's actually breaking, the health you're not looking after, is the part where your effort changes the level for good, because those are the changes that don't wear off in either direction.

So the answer to "why bother" is that you bother about the right things. Leave the job that's harming you, and expect the leaving to keep working, because you've removed a cause. Don't leave a job that's merely ordinary in search of a rise, because the rise has a season. The Diener review said baselines can change under some conditions. It didn't say the conditions were a bigger kitchen. The rest of this book is about what they might be for you, and most of it is done inside the life in hand.