Nearly everyone wants to be successful, but that doesn't mean that everyone wants the same things out of life. The definition of success is different for different people, and you'll never get far chasing your own personal understanding of the word unless you first pause to consider its meaning.

That's why media mogul Oprah Winfrey recently told Skidmore College grads that every young person needs to be able to answer the following four questions if they want to be truly successful in life, according to CNBC's series on this year's notable commencement speeches.

1. What is your inner voice telling you?

"Everybody has what I call this instinct, this inner voice. Every decision I've ever made that led me to the right space and place in my life, I got there because I relied on that inner voice," Winfrey said, citing her own decisions to quit a stable job to start her own show and to take equity rather than a salary at her new venture.

As we all know, those decisions made her one of the richest and most respected women in entertainment. Being successful on that scale requires being a leader, not a follower. And being a leader -- a pathbreaker -- means listening to your own wisdom, not the conventional wisdom of those around you.

2. What is your intention?

In interviews, Winfrey has repeatedly cited spiritual teacher Gary Zukav as one of her greatest influences. She did so again at Skidmore, insisting Zukav taught her one of the most important principles of success -- you need to live life with intention. Simple wandering or chasing money, fame, or recognition won't lead to true success.

After reading Zukav, "I started to make my decisions on what I intended. What do I really intend to happen from the outcome of this decision or this choice?" she related, "and changing the paradigm from just doing a television show, from just being on TV, to actually intending to be of service to the viewers changed the trajectory of the show. The reason we were number one for 25 solid years is because we intended to be."

3. What are you grateful for?

Science is on Winfrey's side in recommending pondering this question. Counting your blessings actually trains your brain to be more positive, optimistic, and happy -- and happy people are more successful people.

Oprah understands this. "I practice being grateful," Winfrey said. "A lot of people say, 'Oh, Oprah, that's easy for you 'cause you got everything!' I got everything because I practiced being grateful."

4. What is your truth?

Yes, this is a big, terrifying question, but if you want to be truly successful, you need to face it. Doing so might be daunting, but it'll also give you incredible strength.

"Everybody goes through trials," Winfrey warned the grads. "There's going to be a trial in your life. It may be disease, it may be jobs, it may be any number of crises that stand outside yourself to try to tell you who you are. And it is your job to know the truth [of who you are] and let that truth set you free."