Does everyone feel insecure?!?

Have you ever seen "that" girl?!? You all know who I'm talking about. That girl w/ the perfect body, perfect hair, perfect face, beautiful glowing tan skin, just gorgeous. & when you see her you think to yourself "if I looked like that I would never be insecure." Sometimes I wonder if "that" girl has insecurities. I mean how could she right?!? But does she?!? I never been "that" girl. I've always been chubby. Ever since I could remember. I don't think I'm unattractive, but I've always thought if I was skinnier I wouldn't be insecure about anything. Is this true?!? Will I still feel uncomfortable when I walk into a room?!? Will I try to cover up certain parts of my body?!? Does the insecurity ever go away?!? Is there ever a point of trying to mold yourself into something that you find beautiful?!?