I am nearly 50 years old (I’m saying this a lot lately, aren’t I?). I have been on this planet for close to half a century. I have seen the birth of Sesame Street, and watched Apollo 11 land on the moon. I have been witness to some of the greatest technological advances humanity has ever known (thus far!). And some of the worst (reality TV comes to mind here). We are more connected than ever before. And in many ways, more isolated. In my 50 years, the gap between rich and poor hasn’t diminished, but in the Western world our lives have got more complicated and less satisfying. I have seen the insatiable demand for “stuff” cripple this planet, and our spirit. Species are being wiped out, our waterways and seas are choking, and yet we continue to consume “stuff” unsustainably. But this post is not about those big picture issues. There are smarter people than me working that out. This post is about what I have learned in my nearly 50 years on this planet, and I wanted to share what I have discovered, in no particular order of importance:

You are ultimately alone.

You might have all the family, friends, work colleagues and associates, Facebook friends and Twittter followers in the world, but you are ultimately alone. When push comes to shove, you have to deal with life. You. On your own. You must be able to rely on yourself to look after you, because no one else will be able to do it as well. And really, no one else should have the responsibility for it.

It’s all about experiences. And attitude.

I am convinced that the best-lived lives are those that are rich and full of experiences – both negative and positive. That broken heart, travel to an exotic location, that beautiful food you just ate, and that hangover you woke up with, all contribute to a life well lived, and one that has experienced many possibilities. Your attitude dictates how you process those experiences. Are you filled with wonder and excitement at the prospect of doing something new and different, of challenging yourself? Or do you dread it? The twists and turns of life – and your attitude to these forks and pathways and obstacles – are what it make it Oh So Interesting. And gratifying.

Nothing is perfect. Ever.

Lower your expectations and you will be a happier, more satisfied person, because there is no such thing as perfect. There is Good Enough For Now, OK For The Time Being, Blissful For This Period In Time. Sometimes blissful can be sustained for longer than you ever imagined or thought possible, but it cannot be sustained. Perfection as a concept is an ideal, not a day-to-day reality. It is not achievable.

You will lie.

As much as you like to think you are an honest person, you will lie. It is unavoidable. You will lie about small things (you look fabulous – you haven’t changed in 30 years) and you will lie about big things (yes, I do love you and want to marry you). You will lie to save yourself pain, and to ease pain in others. Sometimes you will lie because it is just easier than telling the truth. But lie you will. Just don’t do it often.

Not everyone will like you. Or what you do.

As human beings, we crave the approval of others, even those who exist on the fringes of society. We want others to like us and what we do. But not everyone will. Like perfection, it’s just not possible. There just are too many variables involved in “liking” someone: personality, ethics, background, chemistry, reciprocity, integrity, job, education, habits, fitness level, communication style and so on. The good news is that you won’t like everyone you meet and what they do either.

Only you can look after your body.

Your body can not look after itself. You have to do that, and it takes work. And commitment. And time. And effort. Having a healthy body means that you can enjoy your life experiences as you should: with energy and vigour and resilience. Don’t get caught up with weight issues, although this is part of being healthy. Aim to be strong and powerful and vital. You will be rewarded.

You are not your job.

I have seen both men and women get caught up in the hype around their job titles and pay structures and corner offices and fringe benefits. I have seen men and women make morally bankrupt decisions because they think their job requires it. I have met construction workers who were better people than their CEOs. All your job does is provide you with a means to live your life to your best ability. Nothing more nothing less. The stories that you and others attach to it about status and power and importance are just smoke and mirrors. If you are one of the lucky ones who gets to work and make a contribution to society, all power to you. But you are still not your job.

What do you know for sure?

So. That’s what I know for sure. So far. And I’ll keep adding to this list as I accumulate years. But in the meantime I’m interested to find out: what is it that you know for sure?