When we find an imbalance between our desires and reality we stressed out. It very natural if we fail to set expectations realistically. You may wonder thinking about what could be realistic in expectations. Because every expectation of ours seems most needed. So when it comes to being realistic we can't decide what to choose and how to set.
Let me help you in a simple way!
Don't look at the long term goal, first. Like you want to be a successful business person. Break down what you need to achieve that goal and work on them first. It's not possible to be or do what you want overnight or in a short period of time. You have to work on that to achieve that. It takes time and you have to be slow but steady. So, assuming you will be successful overnight is unrealistic and it will make us potentially stressful.
We all want to do something big in life. But we need to run the race to be there. So making your own track is necessary. Like, don't stress out that you need to learn a new language in six months. Break down it like learning 15 minutes every day can make you achieve that easily, will help you be to get less stress and you will know you stats quickly in a realistic way.
You will see, people claim they didn't achieve this or that. And when you ask them you will get that they didn't make it realistic, they didn't try for it. People say that there's nothing impossible. But that doesn't mean you have to make unrealistic goals. You can achieve anything if you try for it, keep things real and understand your stats on that better.