With hard work. Almost anything can be accomplished regardless of natural ability or not.
I'm sorry, but I have to chime in here. This sentiment is not only flat out wrong, it's actually very detrimental to our kids and society in general today.
I'm a teacher, so I'm trained to see the potential in all my students, but these days we tell ALL of our kids, "study hard, go to college, and make something of yourself - you can be anything you dream." Or some similar boiler-plate cliche trash. It's not true. Not in any way true.
Look, I'm 5'7" so the NBA is out because I can't leap like Spud Webb (though my first cousin was a UT record holder and 3-time NCAA national champion high jumper.) Football is my favorite sport, but I'm small boned, so I'd snap like a twig if I got hit hard by an elite defensive athlete - regardless of my physical conditioning (which can't make my bones bigger or stronger.) Fortunately for me, the world's greatest soccer player, Lionel Messi, is also 5'7". It's just a matter of opportunity. If I had the world's greatest training from the time I was a small child, like he had, and if I set my mind to it and worked at soccer conditioning and skills for 12 hours a day, like he did, then I could be a truly great soccer player. No I couldn't, and it's not even close. I don't have the fast twitch muscles of a world class athlete. I wasn't born with them and agility training won't magically create them within me. My first cousin was born with them, but I wasn't. No amount of polish is gonna turn my coal into a diamond.
I was, however, born with high intelligence and I've put it to good use. I probably had the brain power to become a doctor or some such, but I didn't have the drive, dedication, nor desire, so perhaps I failed to become all I could. You can be so lazy as to fail to reach your potential, but that's not the same thing as saying "if you work hard enough, you can be anything." NO YOU CAN'T. It's horrible for our children's self-esteem. You see, if they didn't make the team, it must be because they are too lazy to work hard enough. If they didn't make a 34 ACT so they could get a full academic scholarship to UT, it must be because they didn't study hard enough. No, many failures in life aren't caused by a lack of effort, they're caused by an unrealistically high goal. Very few humans have the intelligence to achieve a 34+ on the ACT and a lifetime of tutoring won't change whether you're on that list. That lifelong tutor can get you from 32 to 34, but when your 19 turns into a 23, nobody's gonna roll out a red carpet for you.
My first cousin tried three times to make the Olympics and all three times he failed. The goal wasn't unrealistic for him, but it would have been for me. Twice he missed the US Olympic team by one spot, and both times he didn't jump his best. And the Rams didn't win the Superbowl, but the dream was realistic. However, I kid you not, I have a room full of 7th grade boys who think they're gonna play in the NFL, or MLB, or NBA, or for Barcelona to be the next Messi. It ain't gonna happen, for any of them. Period. The data says so. A realistic goal would be make the high school team and see where it goes from there.
Why did I write this wall of text? I don't know. I'm just really bothered by the damage I see this sentiment doing to our young people. "You failed, you must not have tried hard enough." How awful.
AV
TL;DR - Work hard and achieve your dreams! As long as your dreams are realistic.