Entrepreneurs are famously optimistic. They are endowed with a bias toward optimism, according to research by Penn State University. This tends to be doubly true for serial entrepreneurs, who look at each time at bat as an opportunity to hit a home run.

But the entrepreneurial lifestyle can also be extremely stressful. There are long hours, tight deadlines and the looming odds of failure always on the horizon. It can often feel overwhelming and impossible to stay above water.

Yet most entrepreneurs get into the game not just to make money, but to make their work lives more productive, meaningful and enjoyable.

Related: 5 Tips for a Happy Entrepreneurial Life

Despite the challenges entrepreneurs face, there are ways for them to influence their own happiness. Here are five remarkable things happy entrepreneurs take the time to do:

1. Give money. Starting up a company isn’t just about making money, it’s also about being able to give back. Donating money can help entrepreneurs focus on what’s important in the midst of juggling investors and dealing with seed rounds.

Most entrepreneurs want to start a business built to last. Ironically, giving money, rather than keeping it, is the one way to make that money live forever -- because it actually helped someone, and that is eternal.

2. Treat everyone with respect. Being a business owner can lead to an inflated ego. After all, the head of any company makes dozens of decisions daily that impact the future of the organization, and often many people. It’s easy to allow this kind of power to overtake empathy at times, but an inflated ego will only cause heartache and headaches and lead to losing great employees, customers and other stakeholders.

Happy entrepreneurs treat employees and customers with the utmost respect. At the end of the day, if you made a lot of money but hurt a lot of feelings, that is not a successful day. The best way to feel happy about yourself is to help others feel happy about themselves.

3. Don’t sweat the small stuff. There are so many fires to put out as an entrepreneur, and it is easy to become overwhelmed. Have a little faith, whether in a higher power or karma, that things will work out.

Don’t get panicked about every little (or big) crisis that comes up. It’s important for leaders to save their energy for the big dips along the way instead of wasting time worrying about every small pothole.

Related: 18 Things to Do Right Now to Be a Happier Small-Business Owner

4. Try to utilize the company platform to help the community. Entrepreneurs want their work -- and their companies -- to be meaningful to others. Whether it's donating resources or coming up with an internship program to help people launch their careers, the company’s actions should somehow benefit the community.

5. Display gratitude. It’s easy to get snowed under, overwhelmed and let stress take the wheel. Starting up and running a company is no small feat, yet there are plenty of things to be grateful for each and every day. For example, having the eyes to read this article. Or waking up this morning.

Each day of life is the greatest gift, and remembering to be grateful for that can keep us grounded and happy through our challenges as entrepreneurs.

According to a Gallup poll quoted in the book The Psychology of Gratitude, 95 percent of people reported that expressing gratitude made them feel at least somewhat happy. Entrepreneurs should take time out to appreciate all the things they have, both in their personal and professional lives. Celebrate the smallest accomplishments along with the most important things.

The happiest entrepreneurs enjoy their work, give back as much as possible and treat others with respect. These are the entrepreneurs skipping into their offices every morning, and maintaining big ol' smiles on their faces throughout the day.

What do you do to keep happy? Share in the comments section below.

Related: 5 Simple Ways to Express Gratitude Every Day