You never know when your big idea is going to come, which is why Benjamin Wendt carried his journal everywhere for more than 10 years.

As a computer graphics major in college and an avid video gamer, Wendt knew someday he wanted to create his own video game. So, no matter where he went or what he was doing, his journal came with, just in case an idea popped into his head.

The journal was by Wendt’s side through his days at Tennessee Technological University, his move to Chicago, getting married, and having two kids. Finally, four years ago, Wendt, now 38, decided it was time to take the ideas in his journal and make his dream a reality.

The outcome was Wark & Wimble, a “simple but stylish and challenging puzzle game with 81 puzzles.” It took four years of programming, sacrifices, and commitment, but Wendt finally achieved his goal.

For young people who share Wendt’s vision—whether it’s creating your own video game or pitching your big idea on “Shark Tank”—he has tips. What it comes down to, he says, is focusing on something you “really, really want to do.”

Q: For many entrepreneurs, there’s a lot of failure involved. Was this your first attempt at making a game?
A: There were times it got really hard to do. Learning how to compose music, it took a long time to get the first acceptable song for the game. Or, I would run into technical problems with certain platforms. It takes a long time. The biggest thing was, I knew where I wanted to end up. It was more just a matter of not giving up. A big component is I never lost focus and I was always doing something with the game, even it was a tiny bit.

Q: What did creating Wark & Wimble teach you about goal setting and work ethic?
A: I used to do a lot of sketching and drawing, but basically all of my artistic talent I put toward the game. I stopped reading as much, cut out watching TV. Ironically, I stopped playing a lot of video games. Cutting out things that weren't important was key. Another thing that was really helpful was getting feedback when I felt like the game got to certain point where I felt good about sharing it. That feedback is good for keeping you focused, because it makes you feel good–even if it's critical–and it gives you an idea of what you need to do to improve it.

Q: What’s the biggest advice you’d like to give to kids looking to be their own boss or create their own business?
A: You have to be able to finish a project. Before you get into it, make sure you have a solid idea and make sure you have the mental capacity and are committed to it. It should be something you really, really want to do, and for me it was important to me to finish.

I ended up redoing a lot of the game at multiple points: Art aspects, music, rewriting code. You should start small, but you should have high expectations for yourself. Don't get discouraged if you need to redo something. Sleep on it, look at it again with critical eyes, and don't be afraid to do it again, do it again, and do it again until you get it right.