Water fight

It's rainy season in early summer. It has rained a lot in my city this week.
Last night，in order to do something fun，one of my friends suggested a water fight. We both thought it was a good idea. We went to a park where there was a pool. Without holding umbrellas，we had a water fight in the rain. People would have thought that we must be crazy if they had seen us having a water fight on a rainy dark night. We didn't care about how others saw us，we just wanted to have some fun.
In reality，many people are caged by all kinds of rules. They don't have the courage to do something that looks crazy but actually is fun. They hardly follow themselves. This is a tragic fact.

It is not clear what the highlighted sentence means. I think you might want to say this: they don't follow their hearts. However, I am not sure. 

Your writing was generally very clear and you expressed yourself well. Good job!