Rainbows

This is a rainbow over the "Half-Penny Bridge" in Dublin. I have dozens of rainbow pictures from various places around the world, and I was just wondering why.  Other people do the same thing. We are fascinated by rainbows and actually they are most everywhere it rains. Dublin has more than its share. Victoria Falls has them everywhere. The Canadian coast is a good place to photograph them.  Is it because it is a symbol of the end of a storm?  Or, is it because it means the earth and air are clean? I don't know, but I like them.