Principles for life

This page started as an email that I sent to my kids in 2013:

Dear Axl and Stan,

I'm writing this e-mail on the plane from Boston to San Francisco.  Sadly, I don't get to spend a lot of time parenting you right now, so I'm writing you this long e-mail instead.  It provides a list of things I wish I had known when I was 21.

You are still too young to read, but I hope you will read and re-read this e-mail when you're older.  Keep a copy handy.  Needless to say, I'm here to help you in person as well.

I wish I could promise you that life is going to be easy.  I can't.  However, I can promise you that it is really worth it, especially if you live by the following principles.

I love you,

Dad

I've maintained this list on since. My last edits were in January 2022.

Principles to live by daily

Exercise your brain continuously: keep it busy. Play chess or other strategy games. Write a journal. Keep your brain buzzing.
Travel as much as you can. My first trip to India blew my mind and changed me forever. Let's go anywhere together, especially if it gives us an opportunity to learn something new.
Food: Learn, experiment, try out, taste all different types of foods. I find it to be one of the greatest things in life.
Learn about finances. Even if it sounds boring, or not applicable immediately to you, learn about finances. To make money, you need to understand money. It's why I've talked to you about investing since a very early age.
Get exercise to be part of your weekly routine. I'm still not great at this myself, but I've seen the benefit. Being busy is a poor excuse.
Don't spend more than you earn. Start saving now. Get into the habit of saving, even if it is only ten dollars/euro every week. Try to build up 6 months of living expenses in a savings account, and invest the rest in high-quality companies or index funds.
Embrace your emotions. Laugh when you can and allow yourself to cry when you have to. Sing out loud. Dance in the kitchen while doing the dishes. Laugh at stupid jokes until your stomach hurts. Cry. Crying doesn't mean that you are weak. Since birth, it has always been a sign that you are alive.
Appreciate music. Listen to as many different genres as possible. Music has a healing function. If you're curious, here is a list with some of my favorite music. Most of these songs helped me in life.
Read as much as you can. I love reading biographies, business books and academic articles. More things will make sense to you when you read often.
Love the outdoors. The more you are out and away from your desk, the greater the chance of enjoying life. Get a good hammock or a camper van. One big enough for more than one person.
Don't take things personally. The hurtful things people say nearly always have far more to do with their own unhappiness than anything else. I've been dealing with criticism for many years; it gets easier over time, but can still hurt.
Seek to understand. Don't make assumptions. Don't assume you know what someone is thinking or why they're acting like they are. Ask and you'll nearly always find out that your assumption was wrong.
Always do your best. Your best on one day, may not as good as your best on another day but always work hard. Celebrate results and outcomes, but not the hard work itself.
Work hard but never hide in your work. When unhappy, working more will never change the outcome. I've made this mistake many times.
Go on holiday with your friends. You'll remember these holidays forever. I still remember every holiday with friends.
Take your time. There will be a lot of decisions and opportunities in your life. When the decision is irreversible, give yourself time and space to think it through. When the decision is easily reversible, don't overthink it.
Spend at least one year living in a foreign country. It will change the way you look at things and make you better at everything else you'll do in life.
It is 100% okay to be different. We need more diversity, not less.
Learn to say "No". The earlier in life you master this, the better off you will be. Hesitate or be too courteous to say "no", and you can end up burdening yourself. I was really bad at this in my twenties and early thirties, but have come a long way.
Deliver on your word. They say your word is worth more than your weight in gold. It is true.
Be ambitious but realistic. Keep away from those that try to belittle your ambitions. Small people will do that. The really great people will make you believe that you too can become great.
Success doesn't come overnight. We tend to greatly overestimate what we can achieve in the next 10 months and greatly underestimate what we can achieve in the next 10 years.
Accept that life will f*cking suck at times. Life is not always easy. Fight for what you care about and don't give up. Things will often seem impossible until they are done. In the end, the hard experiences will make your life meaningful. Sometimes things fall apart so better things can fall together. It become worse, before it gets better.
Your life will not turn out the way you expect it too, and in the end that is a good thing. I didn't know when I was 21 that I was going to start a company in Boston. If your future turns out exactly the way you plan, that means you're living the plan of a 21-year old, and that should give you pause.
Don't settle. In everything you do, keep your standards high. When it comes to the important things in life, the details are not the details.
Be real. Don't fake. When talking or writing, try to tell the deepest truth -- don't hedge with a partial truth.
Don't be afraid of life being difficult and scary. In fact, do what scares you. Take chances. It is the best way to grow as a person.
If you have kids yourself, work hard to give them a life that was at least as good as yours -- if not better.
Focus on what you can control. Don't to worry about what you can't control.
Remember that you only have one life. Waste it wisely.
Apologize when you should. I hope you live a life that you are proud of, and that if you find that you are not, that you have the strength to apologize and start over again. Be good men.
Find out about your parents. They are way more interesting than you think. :)