When I took a shower today, it reminded me of a conversation I had with a security guard back when I was in college. He said that whenever he has a bad day or is in a terrible mood, he takes a shower. It not only cleanses him physically, but to him, it symbolized a total cleanse. He would imagine the water washing away all his anger and other negative emotions.
Water is a universal symbol for cleanliness. Many different religions use water to purify. For example, Christians use water to baptize their followers by "washing" away their sins.
When I take a shower, I feel not just clean, but also rejuvenated. It's like I'm a newer and fresher version of me. Maybe a shower isn't just a shower.