Did you get the impression they were ‘stressed’ about their excursion to buy their coveted item?
Seems to me the article is a classic example of someone following Mr Koch’s advice and doing something that really makes them happy.
I would say this bit of the interview you linked to is most relevant:
Avi: What are “Happiness Islands”?
Richard: I encourage people to think about the small chunks of time - this week, this year, the years during their whole lives - that have given them far more happiness than most of the rest of their time. I call these periods “happiness islands”. Try it for yourself. Ask what the happiness islands have in common - why were you unusually happy then. You can do the same for your “achievement islands” - and for the opposites too, the times when you were least effective (“achievement desert islands”) or happy (“happiness desert islands”).
