why rainbow is so unforgetful?

Why rainbow is so unforgetful? Since I saw the rainbow first time, I was impressed by its beauty. Its colors,which inlcude red, orange, yellow, green, blue, indigo, and violet, joined together and formed such a fantastic view. I wanted to reach my hands to touch it. It is a dream. if it is not dream and I really can get there, will it still be so beautiful as I saw? I doubt it.I think its beauty in my eyes is from distance. But why I still dream to touch it? I know it is made from drops just like the tears in my eyes. Nobody knows I have cried for a rainbow... I hope it knows. But would it care? I don't know. I wish it has a heart as beautiful as the one I saw the first time...