College campuses are filling up across the country as more than 20 million students get ready to start another semester. And it turns out Warren Buffett has one piece of advice about the best investment those students can make.

The important question
At the 2008 annual Berkshire Hathaway (NYSE:BRK.A)(NYSE:BRK.B) meeting, Buffett was asked:

I teach at a community college in Florida, teaching students to invest in themselves. Financial independence and freedom. Slow and steady wins the race. Law of reciprocity, etc, etc, etc. What else should I be doing?

It's a sensible question. With so much discussion surrounding whether or not college is actually worth the money -- and Pew Research Center shows it clearly is -- and student debt loads climbing, it's natural to wonder what Buffett himself thinks of it all.

After all, the Wall Street Journal reported in March, "the only thing growing faster than the sticker price on a college education may be the debate around the value of one -- particularly if a student majors in something with no obvious pathway to a decent job."

But Buffett's answer may surprise you.

The honest answer
He replied honestly:

The most important investment is in themselves...I tell students that you get only one body and one mind. You'd better treat them the same way. It's hard to change habits at age 50 or 60...the best asset is your own self. You can become, to an enormous degree, the person you want to be.

College can so often be perceived as simply a time for fun and fun only. Consider that last summer the Huffinton Post ran 7 Fun Things You Have to Look Forward To In College, with the first three being, "Theme Parties, Greek Life, and School Spirit."

There was no mention of the knowledge which can be gained both inside and outside classrooms, the prospect of finding a major which leads to a fulfilling career, or any of the core benefits college offers. Instead it was only the secondary things that may be enjoyable, but are by no means the purpose of college. 

I say that not judgmentally, but just as a matter of fact. College is intended to be, and should be, a wonderful season of life. But at its core, it's one in which we learn the things to prepare us for our future careers and callings based on the gifts we're given.

Does that mean we should all be investors like Buffett? Of course not. He himself has said:

Never give up searching for the job that you're passionate about. Try to find the job you'd have if you were independently rich...Forget about the pay. When you're associating with the people that you love, doing what you love, it doesn't get any better than that. 

But what it does mean is that college must be viewed as a time to learn, to grow, and to better understand who we were made to be. Do students leave at age 22 and have the rest of their lives planned out? Maybe some do, but for many -- including myself -- that changes very quickly as the real world sets in.

As a result, those years spent on campus must be viewed principally as a season in which much can be gained that can in turn equip and prepare students for the rest of their lives. No matter what you study or where you find yourself, see college first as a season to learn and grow. You'll be glad you did.