You're listening to the happy pod from the BBC World Service.

Hello, I'm Oliver Conway, and in this edition...

It's legendary.

It's about life.

About life as a whole, you know.

Cheese is life. I find out why the ancient sport of cheese rolling is so popular. The man who saved a stranger's life gets a special visit. When an

email popped in, it was just, it was like all my Christmases quite seriously had come at once.

It was a beautiful moment.

And it said, dear donor, thank you so much for the gift of your stem cells.

The creator of a therapy project, which has spread across the globe.

Over 300,000 people sat on a friendship bench to talk to one of our grandmothers,

and 80% of them found it meaningful and got an improvement

in their mental well-being.

And the nun who's taken the internet by storm with her beatboxing.

We start in southwest England, where I went to watch the ancient sport of cheese rolling.

The annual event sees people throw themselves down an incredibly steep hill after a three-kilogram wheel of double Gloucester.

The cheese, which can reach speeds of up to 100 kilometres an hour,

is won by whoever gets to the bottom first.

The tradition dates back centuries,

taking place even in wartime when a wooden replica was used because of rationing.

And today, it's more popular than ever.

Well, it certainly looks steep. I'm at the top of Cooper's Hill, where the first cheese is about to be rolled down. And a couple of dozen competitors are getting ready to chase

...