9 pieces of advice I'd give to my younger self, according to a neuroscientist and business professor

• Moran Cerf is a professor of neuroscience and business at Kellogg School of Management.
• He regularly answers questions about psychology, business, and behavior via email from people who attend his talks.
• This week, he shares nine pieces of advice he'd give to his younger self to have a flourishing life and career.

Q: What advice would you give to your younger self?

A: This is a loaded question with many nuances, but also one that offers a good way to reflect on things. Here are the nine pieces of advice I'd give to my younger self.

1. Invest in people - they show the highest ROI

My students often ask me, as a business professor, what is my investment recommendation. I half-jokingly say, "Lobbying, because people are cheap." Unfortunately, this is becoming truer by the hour. If you buy someone a sandwich and accompany that with some conversation and nice comments about a picture of their kids, and then six months later call in a favor, that person typically will deliver.

Here's the non-cynical answer: About 18% of startups fail because of disagreement and friction between the founders. The biggest financial strain on most people is their divorce, and what causes people the most stress is an unhealthy relationship. Point being, investing in finding the right people - partners in business and in life - is critical.

Easy ways to start forming relationships: Remember people's important dates (birthday, anniversary, etc.) and call them on those dates, remember their kids' names, listen when they speak, and ask questions about what they said.

2. Calculate the value of your time

Determine how much an hour of your time is worth at any point in your life is worth. Then decide - whenever you give up your time - whether you are OK sacrificing that amount of money.

Spending five years of your life doing one thing, be that getting a degree or having a job, in your prime years (mid-20s to mid-30s) is invaluable. You should learn to recognize the value of your time as soon as possible, as it's one of the few assets you can't increase.

3. Learn to quantify luck

Most of us think of luck when we want something that is unlikely to happen and it does. Similarly, we think we're unlucky when something we don't want to happen still happens nonetheless.

Here's a way of quantifying luck: Freeze your life for a moment and imagine what you would give to be in the very situation you have right now if things one day turned bad.

For example, every time you drive home and speed above the limit and don't get a ticket, think of it as a lucky moment. Then, when you do get a speeding ticket, you should divide its cost by all the other times you didn't get a ticket although you deserved one. That's how you can remember that you were lucky many times before and just didn't notice it.

Want another refresher? If you're reading these lines, it means you have a computer or a cell phone, you are literate, and are healthy enough to care about things outside of your survival. Make a mental note of that.

4. Take financial risks proportional to your age

Just as you want to diversify your investments perpetually, you want to tie your risk to your age. When you're younger (say, in your 20s) you're able to afford to make mistakes and try again. At this age, not trying is the biggest mistake. That person you didn't ask out because you were shy, that call you didn't make to a friend of your parents who was starting a business, that course you didn't take in college because it started at 8 a.m. are critical in your 20s. They are less critical in your 50s. So make more of them when you are young.

Here's the diversification part comes in: Put money in safe investments younger. The key to making money in the stock market is time. Not timing, time. If you're able to wait long enough, you can make a fortune.

5. Be rebellious

This one could get you in trouble. It could also get me in trouble for advocating for it. But I'm willing to take the risk (see bullet 4).

You should train yourself to do things that stretch the boundaries as much as possible whenever you can. History suggests that pushing the boundaries and being rebellious (in forms of activism, opinions, business ventures, research, and many other domains) proves useful.

If everyone walks to the right and you train your brain to think "what if I walk to the left," you'll at least learn that other options exist. Maybe in due time you'll land on an idea that no one thought of or find a new path that no one saw.

6. Keep a diary

This advice appears in my final session at my Kellogg business class when I give students some "free advice for life." Many of our students want to find a big startup or innovation idea. Here's another way to find your big idea: Keep a diary.

Whenever you encounter something that doesn't make sense - write it down. Your next startup is there.

You walk in the rain with an umbrella, but your shoes still get wet - a startup. You are annoyed that you need to separate the white shirts from the colored one before you do the laundry - a startup. You can't understand why the line keeps disconnecting during your call with customer service and when you restart you have to go over the details again with the next agent - a startup. My list is long and full of these ideas, because I keep a diary.

Those geniuses who had great startup ideas are not smarter than you, nor are they luckier (see tip #3). They just made a note of something in the world that you saw too, but didn't register.

The diary could be a recording or scattered pieces of papers that you combine once a year. But they have to be registered in the moment. Otherwise, you will forget, and when the time comes for an idea, you'll think that you have none.

7. Don't follow your passion

I recently had a conversation with two colleagues of mine - professors Scott Galloway from Stern School of Business and Sinan Aral, from MIT's Sloan - where this topic came up. Scott explained it better than me, but I'd summarize with this: "Follow your passion" is terrible advice. Instead, follow what you're good at and do it in a fantastic way. It will gradually become your passion. People love what they do when they do it perfectly.

8. Have a sense of humor

I recently finished reading Viktor Frankl "Man's Search for Meaning." I can't do justice to his articulation of this advice, but if I were to rephrase it in my own words, it would be, "If you're able to find humor even in the darkest moments, then you will be able to endure the toughest times."

I was once in a room where a colleague of mine, Dr. Yossi Vardi, made the CEOs of Alcatel, Intel, Wix, and Orange wear clown hats while taking serious questions from kids about their role as CEO. I asked him how he got them to agree to that. He said he reminded them that their sense of humor was crucial in getting them to the position of CEO.

9. Develop self-control

Research shows that being able to exert self-control is correlated with health, good relationships, and successful business decisions. How do you train your brain for self-control? You practice.

Here's how: Choose one thing that you don't do - and stick to it. I, for example, decided at age 14 that I would never drink coffee. Accordingly, I have never tasted it. Ever. You can do the opposite - decide that there's something you will do daily. Say, spend a minute doing push-ups. This exercise can be as easy as a one-minute thing, but you have to do it daily. That's the way to train your brain.

Moran Cerf is a professor of neuroscience and business who explores how we can harness our understanding of the brain to improve our behavior, our business, and society.