At the end of 2015, I felt stuck. After a near-death experience, I had to quit my job and retire early to prioritize my health.

My health improved, but the rest of my life did not. I felt bored and purposeless in retirement, and my relationships suffered. I started to wonder, “Is this all there is?”

In search of answers, I signed up for a 30-day silent retreat in St. Beuno’s, a former Jesuit seminary in North Wales that’s now a spiritual retreat center.

At first, spending 30 days in silence was harder than I thought. But I was eventually able to meditate on how to live a happy, regret-free life.

Here are four lessons I took home with me:

1. Trying to control outcomes will make you miserable.

Before the retreat, I was a control freak. The idea of “letting go” in any part of my life was out of the question.

Nestled in Denbighshire, Wales, St. Bueno’s has been a retreat center since 1980.

Photo: George Jerjian

But during an exercise at St Bueno’s, I was asked to think about what I truly had control over. I realized that just one unanticipated event could send my life into chaos. I reflected on how much time I spent worrying about outcomes that I couldn’t predict or control.

Now, when I want something good to happen, I imagine that it has already happened and feel grateful for it. This mindset helps me move forward. By focusing on taking the next steps, I am no longer focusing on the outcome.

2. If you’re not thankful, you’re not thinking straight.

Research has shown that gratitude blocks toxic emotions like envy and regret, reduces stress, and improves happiness.

During the retreat, I was in a challenging period of my life. At one point, I was asked to reflect on all the homes I had lived in, and what good and bad things happened there.

It dawned on me that no opportunity in my life could have come about without the preceding crisis, so I should appreciate every moment.

Try this exercise: Write down all the great times in your life, or the moments you are most proud of. Then, next to it, list the difficult moment that gave you the skills or created the opportunity to achieve those goals.

3. To find purpose, follow your passion.

Money always came first in my career. I never stopped to ask questions like, “What work should I do based on my interests and feelings?”

During the retreat, though, I had nothing to think about but my feelings.

Three weeks in, I broke down weeping thinking about all the people I had hurt. But on the last day, the tears came from a place of joy and love. I realized that my true fear was hurting others, and that my passion was helping people.

I had a lot of time alone at St. Bueno’s to reflect on my life and the beauty of the nature around me.

In the years after the retreat, I chose to unretire and serve retirees with my coaching business.

Ask yourself: “What am I most afraid of? What activity do I lose all sense of time in?” Try answering these questions five times, and each time provide a different response. The answers might surprise you.

4. We are not always who we think we are.

For 60 years, I constructed a persona based on what my parents, teachers, employers, partners and friends wanted.

I never thought about who I was beyond those external pressures. I had spent decades lost and ashamed of who I really was.

Think about whether there’s something about yourself that you hide from the world. Try to embrace that thing. For me, it was gentleness and understanding that changed my life.

George Jerjian is the author of “Dare to Discover Your Purpose: Retire, Refire, Rewire.”

CNBC