What is creativity? While there's no easy definition, I like the one from researcher Sarnoff Mednick who defined it as an associative memory that works very well. 

Mednick's Remote Associates Test attempted to quantify creativity as the ability to see the commonalities of three word sequences like "fish-mine-rush." (The common element there is "gold.") 

While not universally accepted, I think there's something to the idea that exposure to new ideas, people and cultures is the cornerstone of creative thinking. Greater exposure builds your associative memory and ultimately will make you more creative in business, from securing new clients to entering new marketplaces and attracting new talent. 

But getting that exposure takes effort and a certain amount of mental toughness. Here are a few ways to do it:

1. Read more than the industry trades. 

It's easy to get into a rut of only reading about your industry.  That's because these days, there is endless content out there. You can do a deep dive on just about any topic related to your field. 

But, even if you love your field, you can benefit greatly by reading about what else is going on in the world. 

That doesn't mean you have to keep refreshing USA Today or The New York Times all day. Consider other sources of potential inspiration, such as architectural or fashion publications like W, Architectural Digest and Vogue or pop culture outlets such as People and Vanity Fair.  Of course, any periodical should offer new information. I

If you expand your reading sources, though, you're less likely to be drawn into familiar topics and more likely to hear something genuinely new. 

2. Cultivate a life outside the office. 

Everyone is working more hours now and our smartphones act as digital leashes that keep us tethered to our work. 

Even so, we all benefit by carving out time to cultivate an identity that's separate from our professional life. Follow your interests. If you like to run, join a running group; or, take a yoga class.  Interactions such as these promote the formation of "weak ties," also known as acquaintances. 

These types of relationships have been found to be extremely important conduits for passing information. In fact, you're more likely to hear something new from an acquaintance as you are from a close friend.

3. Approach the world with curiosity. 

Curiosity saves conversations from becoming dull and moments from becoming boring. 

Before smartphones, while we were waiting in line at the bank or post office, we used to strike up conversations with strangers.  That's becoming a lost art, but I find that most people respond well to genuine interest. By engaging with strangers, you are more likely to learn a new perspective or get new information. 

As Kio Stark noted in her TED talk on the topic, you are also more likely to attack your own biases and see people of different groups as individuals.

4. Learn a new hobby. 

A study of scientists found that the average scientist is as statistically likely to have an artistic hobby as any other member of the public, but eminent scientists -- members of the  National Academy of Sciences and the Royal Society -- are about twice as likely to have such a hobby and Nobel Prize-winning scientists are around three times as likely. 

My theory: A hobby prompts you to create a filter of looking at things from a different perspective, which broadens your associative memory. 

Learning something new is also very good for our brain health throughout all stages of life.

5. Attend different types of events. 

Reading about something is great, but nothing makes an impression like an experience.  That's why I advocate attending concerts, seminars and events from industries outside of your expertise. 

Perhaps you can move into a totally new industry, like Elon Musk did. Musk was a co-founder of PayPal, so his background was in fintech. Since then, of course, he has moved into electric vehicles and space travel. 

One's ignorance of a new category can even be an advantage, since it allows a person to access that new category from an unbiased vantage point. 

There are countless other ways to broaden your thinking. All of them fall under the heading of "get out of your comfort zone." As the old saying notes, this is where life begins. 

There's a reason why people resist leaving their comfort zone though -- it's uncomfortable. That's why cultivating creativity requires some teeth gritting and mental toughness.

If you don't consider yourself mentally tough, then toughen up! Begin with small challenges to boost your confidence and grow from there. Being truly creative means facing rejection and criticism and not being afraid to fail.

We don't necessarily think of creative people as tough, but they are. You can be, too.