What does it mean to revolve your whole life around your sexuality?

I am getting more active via the Internet on many Homosexual themed forums and I've noticed this appears to be a common catch phrase amongst the members/users "I don't revolve myself around my sexuality, my sexuality only makes up a small part of me." Isn't that a given that your sexuality is only one part of you? So why the need for the qualifier? I never hear Heterosexuals, Lesbians or Transsexuals say this. So why the need for Male Homosexuals to?