Doctors and psychologists alike have long known the power the way in which we think affects our life. Especially as we age, experts notice that those who continue to think they are younger, actually act younger, and therefore stay healthier and in better shape as if they were younger.

So instead of worrying about the aging process, it’s time to realize that youth is a mindset, and that you can take steps to keeping yourself young just in the way in which you think.

Age is just a number. As you’ve probably already noticed, even if you share a close birthday with someone, and are effectively the same age, you may be worlds away in maturity, mentality, and success. This is why changing your mindset can effectively change your age, because age isn’t a concrete thing.

It’s a collection of experiences, thoughts, and emotions that humans experience which propel them forward in life. Although the number of years you’ve been on this earth may seem like a lot, remember, you don’t have to listen to society, and that you are only as old as you want to be.

As children, humans are always exploring. Touching, tasting, and asking questions about new things. And many people often think that childhood ends when you stop growing physically. But children aren’t just growing physically, they are also in a state of constant mental growth as they experience the world.

Stanford psychologist Carol Dweck calls this the “growth” mindset and according to her book, keeping your mind in this region of growth will help you effectively feel younger.

The opposite of a growth mindset is a fixed mindset, and Dweck believes that those stuck in a fixed mindset will quickly find themselves burned out, and tired, because they will feel the need to prove what they know (within their narrow scope of mindset) over and over again.

It is this constant vying for approval which places stress on the body and causes us to feel older than we are. In order to stay away from the trap of a fixed mindset, Dweck advises to always try new things, face challenges head on, and own up to your mistakes. Keeping your mind open to new adventures and challenges will keep you from feeling the need to prove yourself, or falling into a mindset where you will be unable to grow.

Besides just trying new things, continually learning something new will help broaden your mental horizons and help you feel young. Remember as a child when you first learned to do something new? Remember how proud you were?

Chances are you may not feel this feeling as much as an adult, but this doesn’t mean you can’t. Try learning a new skill that you’ve always wanted to learn. And make sure you stick to it. Once you learn how to do it effectively, you will likely feel the same sense of accomplishment as you did when you were a child and this will help you to feel young both mentally and at heart.

And don’t be afraid to look back at your past as a number of studies have shown that reminiscing about good times actually helps seniors live longer, as it keeps the mind on a positive track and keeps them away from negative mindsets.

The point is, you are truly only as old as you believe you are, so don’t let anyone else tell you this number. Age is only allowed to progress if you let it, so keep yourself looking and feeling young for years to come by staying in a youthful growth mindset, and approaching the world just as you did when you were a child.