Opinions expressed by Entrepreneur contributors are their own. When establishing a startup, you're bound to run into obstacles that seem insurmountable. After all, starting your own company is no easy task. You'll be faced with constant challenges that test your resolve and ultimately determine the success of your business.When founding my own company, there were many times I was disappointed at the lack of progress or the problems arising. Fortunately, I learned how to deal with tough situations appropriately and how to build a successful company. All it took was time and a willingness to learn and grow from my mistakes. However, no one should go into founding a company blindly. As I said, there's plenty I wish I'd known...