I think the principle is true in other areas of life too, including happiness through tough times.
No matter how difficult some days are with Gabrielle, each and every day Amy and I make an effort to focus on the good things ... the miraculous things. Every day is a choice. We both know that, in a matter of days, we could let our minds go down deep, dark paths should we let them. But we don't. They're scary and dangerous. Instead, we choose to be happy – despite the grief – for our kids, for each other, and for ourselves.
And it looks like we may have stumbled upon something that scientists have only recently turned their attention to, which, to their credit, is awesome, but which, like so many other things about research, is just so darned funny when you think how natural and intuitive it is. Anyway, check out Dan Gilbert's talk below. I watched it last night and, if you're like me, I guarantee it will challenge some of your assumptions about what makes you happy too.
FYI: his best-selling book is Stumbling on Happiness.