Millennials and Gen Z have come of age in an era marked by sweeping change. So their milestones, especially when it comes to retirement, will look different than older generations' did.

Life rarely turns out exactly how we expect. In my early 50s, I was forced to retire early after a near-death experience to take care of my health. But at 62, after feeling bored, restless and stuck, I un-retired and started a coaching company to help people achieve a more fulfilling retirement than I did.

Here are four myths about retirement that more people need to talk about:

Myth #1: Life follows a linear path.

Many baby boomers believe that life has three major chapters: Get an education; get a job and get married; and retire and enjoy the downtime.

But life is much more elastic than that. People in their 60s and 70s start new careers and new relationships all the time, and young people can achieve a life of balance before age 65.

Don't wait for retirement to live the life you want. Tomorrow is never guaranteed, so take time to do activities you enjoy every day.

Let go of the pressure to figure everything out. At 62, I started a business I would've never imagined in my 20s or 30s.

Myth #2: You can't teach an old dog new tricks.

As children, we are so curious. But I've found that in my generation, the older we get, the more we stop asking questions.

The brain is a muscle that needs exercise. Learning helps us feel engaged with the world, and it's good for brain health and memory.

Dive deep into things that you're interested in. For example, I love learning about how our minds, personalities and identities work. Or you could pursue a hobby where there's always room for development, like gardening or starting a charity.

Myth #3: Your 20s and 30s are your best years.

Our consumer society has created the narrative that everything and everyone has a sell-by date.

But up to half of the 5-year-olds in the U.S. today are expected to live to 100, according to Stanford's Center of Longevity. Young people can't just decide to expire at 65. They'd be sitting around for almost 40 years.

The Roman philosopher Cicero wrote: "Old age is the crown of life." Watch elders who are active and happy. Ask them what physical, mental, and community activities keep them engaged. You may be surprised to learn that they actually feel ageless on the inside.

It won't be too long before you become an elder, too, so it's in your best interest to discover what challenges you will be facing and what joys you can discover.

Myth #4: There's no point in thinking about death.

Keeping death at the top of mind might sound strange, but until the age of 52, I thought I was immortal. Then my oncologist told me I had six months to live. The diagnosis was thankfully wrong, but what a wake-up call.

Benedictine monks are encouraged to "keep death daily before your eyes," so that they can live life more fully and in a detached manner.

I found that remembering death can come at any time eliminated my mindless pursuits and worries. It allowed me to be more present and do more things that were actually important to me.

Cultivate your own garden

My best life advice is to have compassion for yourself. And whatever you do, follow your own north star. Each person has a different beautiful and difficult journey.

Keep doing what you love, master your skills, and acknowledge your progress.

When you cultivate your own garden — your unique skills and passions — you are always awake in your present moment.

George Jerjian is the author of "Dare to Discover Your Purpose: Retire, Refire, Rewire." An Emmy-award-winning producer and author of 10 books, he earned his business degree from Bradford University in England and a master's degree in Journalism from New York University. Follow him on Twitter @GeorgeJerjian.

Don't miss:

• A 67-year-old who ‘un-retired’ shares the biggest retirement challenge ‘that no one talks about’
• A longevity expert shares the exercise she does to live longer and prevent her body from ‘aging fast’
• A 67-year-old American shares what retirement is ‘really’ like—with ‘no work and all that free time’

Want to be smarter and more successful with your money, work & life? Sign up for our new newsletter here

Take your business to the next level: Register for CNBC's free Small Business Playbook virtual event on August 2 at 1 p.m. ET to learn from premier experts and entrepreneurs how you can beat inflation, hire top talent and get access to capital.