This is NPR's life kit.

I'm reporter Andy Tagle.

What shape does gratitude take in your life?

Have you ever thought about it?

To me, something about the word gratitude

just makes it feel big.

Like, I'm reminded of handwriting hundreds of thank you cards

after our wedding, or their pressure to say

just the right thing when you're giving a toast for someone's birthday.

Making sure to eat every last bite on my plate

so my grandma wouldn't think I was ungrateful for my meal.

Capital G gratitude is powerful.

And sometimes that can make it feel heavy.

Like a complicated tool that needs a lot of time and effort

and a user's manual to wield correctly.

But Christina Costa, a psychology teacher and PhD student

at the University of Michigan,

says it's really much simpler than all that.

I always say start really, really small.

I am so grateful for the sun today.

Christina's area of study is positive psychology,

but the focus on resilience and well-being.

...