One of my best friends and I have a 57-year age gap. He's taught me life lessons, like staying young at heart.

• I struck up a conversation with Bryan in a coffee shop four years ago and we became friends.
• At 95, he's 57 years older than I am. We have different experiences, and a lot to teach each other.
• I've learned so much through our friendship, and I'm grateful he's in my life.

I was feeling a bit down and worn out from life when my phone lit up with a message.

I opened it to discover the most beautiful photo of a dazzling red rose in bloom. The sunshine makes the petals look as though they are 3D, like I could almost smell their scent. I instantly felt better.

"Just something to brighten your day," the message read. It was signed off by SAR, a fun acronym my friend Bryan uses for "Stone Age rocker."

I smiled as I pictured my good friend in his flower garden. He was probably about to go for a spin around the neighborhood on his mobility scooter before charming the ladies at the local bakery.

It's been four years since I struck up a friendship with Bryan, who happens to be 57 years my senior at the age of 95, and in that time he's become one of my closest friends.

Our friendship has taught me so much about life and love, about what's important and what to let go of. Here are some of the lessons I've learned.

Say 'yes' to more opportunities

Bryan has lived an unconventional life. He's a free spirit, uninhibited by traditional societal ideals.

Instead of working the same 9-to-5 job for 30-plus years, Bryan made a decision when he was younger to only ever spend a few years in a role at a time.

He's tried his hand at many different things, from working as a machine operator at General Motors while they were manufacturing the first model Holden and being asked to chauffeur Miss Australia contestants around in it, to being employed as an assistant cinematograph operator, limousine driver, sales rep, and high school facilities manager.

In his younger days, Bryan was personally invited to open a bike shop in Tasmania by Sir Andrew Bruce Small, a well-known Australian bicycle manufacturer, land developer and politician. Later in life, Bryan and his wife Mary traveled all over Australia, house-sitting along the way.

Bryan has always been a 'yes' person who seizes every opportunity that life offers.

Stay curious

Generally, I find people of my age (in their 30s) to be quite self-centered. When I strike up a casual conversation, I find it tends to be pretty one-sided. I end up asking the other person all about their lives and experiences, probably because of my background in journalism.

Bryan is different. He always wants to know how I am feeling, what I think about current affairs, and what my family is up to. He also has this insatiable thirst for knowledge, which I find so inspiring. He often has interesting hobbies and projects on the go, whether it's writing a book or learning French.

At 95, he is still actively learning.

Love fiercely

When Bryan first told my husband and me about his late wife, his eyes filled with tears. It was clear how much he loved her. Their bond was so special that they often dressed alike.

Their relationship has given me and my husband something to aspire toward. Nowadays, it's rare to love so unconditionally and deeply for a lifetime.

Don't take life too seriously

One of my many flaws is that I tend to sweat the small stuff. Bryan is the complete opposite. He has this beautiful way of making light of a crappy situation.

Take, for example, his mobility troubles. He experiences knee pain — which he calls his "kneemonia" — but he never lets it get him down, and refers to his mobility scooter as his "limo.

The glass is always half full with Bryan.

Stay young at heart

Bryan loves to say, "The bod might be 95 but the brain's 49." He doesn't consider himself old, and nor do I. He is still so young at heart, and effortlessly cool.

He loves my hole-ridden jeans, the ones my own older relatives turn their noses up at when I see them. He signs off his messages to me with hilarious GIFs. He even has a Facebook account.

Be grateful

They say that the root of happiness is gratitude, and Bryan is proof of that. He is so grateful for everything, whether it's a cup of coffee or a phone call. And he is so content.

Last year I found out Bryan has an aneurysm in his abdomen. The prognosis wasn't good, but in true Bryan form, he's kept positive about the situation.

I am so grateful for the friendship we've shared and for the time we have left together. I will carry the lessons he's taught me for the rest of my life.

And one day, if I make it to 95, I'll think of Bryan with a smile and remember that time when a stranger struck up a conversation with me and it turned into a beautiful friendship. With a bit of luck, I'll be just like him.