What does this mean to not let your hopes run loose its like a rush with the water under bridges?

The phrase "not let your hopes run loose" suggests maintaining a sense of realism and control over your expectations, rather than letting them spiral out of control. It implies that unchecked hopes can lead to disappointment, much like a rushing river can cause chaos if not contained. The reference to "water under bridges" signifies that, just as water flows and can be unpredictable, so too can our dreams and aspirations if we don't manage them wisely. Ultimately, it encourages a balanced approach to hope and ambition.