Matthieu Ricard, a 69-year-old Tibetan Buddhist monk, has been called the "world's happiest man."

That's because he participated in part of a 12-year brain study on meditation and compassion led by University of Wisconsin neuroscientist Richard Davidson. And Davidson found his brain waves and activity to be off the happiness charts, reports Business Insider.

In 2008, Davidson had a group of expert meditators (including Ricard) and a group of controls (people who were not experienced in meditation) meditate on compassion, he reported in Scientific American.

Then he had them listen to the sounds of several stressed-out voices. Davidson found that two brain areas known to be involved in empathy showed more activity for the meditators than for the non-meditators, suggesting that people like Ricard have an enhanced ability to respond to the feelings of others and empathize without feeling overwhelmed.

He also noted that when he exposed Ricard to an outside stimulus meant to startle him — like an alarm going off unexpectedly or a stranger accosting you in the street —  while he was meditating, he was far less put-off by the stimulus compared with someone who was not meditating.

So, how does the "world's happiest man" feel happy all the time and get rid of anger and stress?

Feeling happy comes down to being altruistic and benevolent, Ricard says. He also believes the mind can be trained to be happy through meditation.

And as for dealing with stress? Ricard says the key is let things go.

Most things you think are problems aren't actually problems

Ricard admits that sometimes, feeling stressed is warranted. "Sometimes there's legitimate stress, like if a rhinoceros is running behind you, it is maximum stress," he says.

Sometimes there's legitimate stress, like if a rhinoceros is running behind you, it is maximum stress.

"Or if you are in a situation that is really oppressing and there's a sense you can't move out of that and you feel so powerless — mentally and physically it's not very pleasant."

Most other kinds of stress — ones that don't cause actual physical or mental harm, Ricard says — should be shrugged off, Business Insider reported.

"This idea of constantly feeling like there's a rhinoceros running behind you is very unhealthy," Ricard explains. "It will destroy your neurons, it destroys your immune system. Basically it happens when we put too much emphasis on our outer condition. 'If I don't have that I can't be happy.' 'If that thing remains, it's just like hell breaking on me.' So it's underestimating that we can say to those things, 'Oh, you know, okay — no big deal.'"

Living a stress-free life just comes down to the way you deal with perceived problems.

Don't worry about things you can't change or control

Ricard admits that of course, problems pop up in life. The trick is to not worry about the ones you can't control, and to focus on solutions for the ones you can.

"Having some kind of inner resources to deal with the ups and downs of life, whether that's resilience or inner strength — that's a huge advantage against stress," Ricard says.

"If something unpleasant happens, just say: 'First, it won't last. Second, I can deal with that because I know I can keep my balance. And after all, it's not such a big deal so okay, no problem.' Or if people criticize you just say, 'So what? Why is this going to prevent me from being healthy and from sleeping?'

"The stress doubles the problem. First you have the worry, then you have to worry about the problem, which is totally unnecessary because if there is a solution then just do it. If there is no solution, then why worry? That's just adding to your problems."