The world’s third-richest man Warren Buffett turned 89 on Friday. Here are five valuable pieces of advice on how to be successful from the investing legend himself.

Marry the right person

According to Buffett, the most important decision of your life is choosing your life partner.

At the 2009 Berkshire Hathaway annual meeting, Buffett said, “Marry the right person. I’m serious about that. It will make more difference in your life. It will change your aspirations, all kinds of things.”

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Invest in yourself

“By far the best investment you can make is in yourself,” Buffett says.

“Take care of your body and mind — especially when you’re young…You get exactly one mind and one body in this world, and you can’t start taking care of it when you’re 50. By that time, you’ll rust it out if you haven’t done anything.”

Associate yourself with ‘high-grade people’

“One of the best things you can do in life is to surround yourself with people who are better than you are,” Buffet said in 2015. He explained that when you’re around people better than yourself, you’ll start acting more like them. Conversely, if you hang around with people who behave worse than you, you’ll start being pulled in that direction.

Work for people you respect

“Try to work for whomever you admire most,” Buffett says.

Buffett says that while salary is an important factor when thinking about your career, you shouldn’t go for a job just for the money. It is also important to consider the experience you’ll gain from it.

Success isn’t measured by money

Despite being one of the richest people in the world, Buffett doesn’t use wealth as a measure of success. For him, it all comes down to relationships and love.

“Being given unconditional love is the greatest benefit you can ever get,” Buffett told MBA students in a 2008 talk.