Hello Mr. Sun is a song by English singer-songwriter Joe Brooks which is about letting go of one's inner battles and worries to live life freely. The song is a metaphorical representation of the freedom and good vibes that come with the presence of the sun. In the lyrics, Joe bids goodbye to Mr. Rain and welcomes Mr. Sun in a bid to rid himself and his listeners of negative thoughts and worries. He encourages everyone to embrace the warmth of the sun and let it ease all their troubles. The song also celebrates people who live their lives without caring about other people's opinions. Joe hails a girl who sings her heart out to the world without worrying about being judged. He also pays homage to a boy who loves his girl and doesn't care about society's standards. Overall, Hello Mr. Sun encourages listeners to embrace positivity, live their lives to the fullest, and not allow their fears and worries to hold them back. It's an uplifting anthem that encourages everyone to focus on the bright side of life and appreciate the joy that comes with it.