Centuries of social conditioning have led us to believe that we MUST marry and we MUST procreate. Therefore, I've failed society's expectations. But why MUST we? Some people just never get married or have kids -- it happens. Some people just don't want that out of life. And that's okay.
Girls are taught that motherhood is a desired natural state; a state which is a normal progression in our lives as females. Even today, the emphasis is on motherhood first, career second, and that is wrong. Motherhood doesn't define womanhood.