You've probably heard the phrase "good things come in small packages," and for the most part, this statement is true. In a whole host of cases, not putting limits on things can be disastrous.
Take for example over-eating a particular type of food, allowing your body to overheat during the hot summer months, or even being over-exposed to radiation. Each of these has the potential to cause major health problems, or worse, death.
The list obviously doesn't end there, but it would be a long and drawn-out read if we continued to list everything out for you.
Many foods and medicines have suggested serving sizes or directions printed on their labels that you should follow to prevent over-dosages. Moreover, you've probably been warned to stay hydrated and utilize shade whenever possible in the hot summer months to keep your body from overheating.
You should try to moderate anything you do or exposed yourself to. Although you can't control everything, imposing limits on certain things can promote better health and help you live a longer life in many circumstances.