Today is M’s birthday. Before the end of the year, it’ll be mine.

We’re getting older. But are we getting old?

Adulthood is an invention by children to explain why adults are grumpy all the time.

I feel older. Time is moving faster because as a percentage of my lifespan so far, a day is only 0.0074%. A year is a fraction over 2.5% of my life.

In the earliest days of my career in IT, at the second company I ever worked for, I sat in on a design meeting between my employer and another company. We were discussing system integration between their product and something we would build.

The details aren’t important, but it gave me insight, at the young age of 20-mumble, that adulthood isn’t a real concept. The “discussion” between both parties was nothing more than a “discussion” I would have had on the playground at school only a few years prior. Each side wanted to get their own way.

This was eye-opening. Adults were just “big kids with more money”, I quipped at the time. Mumble-years later, this is a very cynical and obviously wrong assessment. Adults are just big kids. Some do all the work. Some shirk all responsibility. Some have money, and some have crippling debt. Some have children, and some have children but treat them like siblings. Et cetera, et cetera.

So what separates us from childhood? Well, that’s a philosophical question we could spend weeks puzzling on.

But if you were to ask me (and I’m glad someone did, thank you), I think it’s our experiences. We learn from seeing and doing things.

Much of what happens in our lives, after a certain age, is on auto-pilot. Often I’ll catch myself daydreaming while driving a car. My following distance is good, my feet are working the brake and accelerator pedal, I’m watching my blindspots, but I’m not concentrating on driving.

While this is fairly unremarkable (we don’t concentrate on walking), it’s remarkable for me, because until about ten years ago, I had a sign on my dashboard that said “STAY ALERT”, because I had to concentrate.

Not all of what we do is automatic, however. If we work in a challenging job, we usually do have to concentrate. My brain is always thinking about work stuff: Did I design that database table correctly? Could I use another index on that column? Is the stored procedure efficient?

And meeting people who share the same interests as me is mentally fulfilling. Whether it be games night with Tanya and Mervin, or listening to people speak at SQL Server conferences, I enjoy engaging with people.

Does this make us adults? Are we more sophisticated because we can discuss medical and technical and operational and business topics? How is this any different to the latest Star Wars teaser? What makes, for example, a play or musical any more culturally significant than a film that everyone likes?

Again, that’s a philosophical question I’ll leave as an exercise for the reader. But I find the act of engaging with like-minded people, people who challenge my perceptions, people who introduce me to new experiences, more fulfilling than whatever it is we’re doing.

After Sunday’s game of Settlers of Catan, did I enjoy the game more than the experience of the game? Did I enjoy today’s lunch more than spending time with my spouse?

I’ve now seen countless films, television shows, concerts, plays, musicals and other events, and truthfully, I’ve forgotten many of them offhand. But if you mention the name of an event, I’ll remember with whom I shared that experience, and I’ll probably recall my emotional state in greater detail.

Adulthood, for me, is about having experiences, but even more than that, it’s about having experiences with other people who share the same enjoyment of those experiences. Being able to share my life with other people makes me happy.

Find someone who makes you happy, and share your experiences with them. It doesn’t have to be the same person for all your experiences, though. That’s unfair on both of you.

In my case, I have some friends (and I class them as friends, not acquaintances) with whom I share only one or two interests. I have some friends with whom I share many interests. I have one particular friend with whom I sleep every night, shift-work notwithstanding, and we even got married a few years back.

Adulthood is having a friend to play pool with, and another friend you can knock around on the sports-ball field.

Adulthood is being able to share.