I got this off of Dictionary.Com.
“Pride n. - A sense of one’s own proper dignity or value; self-respect.” Of course, there are other definitions, but I think this one fits best why the word “pride” is used in connection with gay marches, etc… As has been said, for so long gay people have been made to feel that who they are is shameful, sinful, etc… that we want to celebrate and show the world our own value.
I’m glad, Tigerman, that you realize that being gay is a function of biology. Unfortunately, many of our straight brothers and sisters do not. They still see at as choice. And, therefore, they still see it as something to be ashamed of. Hopefully, one day, we won’t have to celebrate “Gay Pride” as no one will be made to feel ashamed to be gay.
In my opinion, though, that won’t happen until we start showing people that there is as much diversity within the gay community as there is in other communities. This means that we have to stand up, even in small ways, to the prejudice and misinformation that is out there about gay people. We need to find ways to “teach” those around us the many ways there are to be gay. And, I’m not talking about lecturing to them. Bare with me as I give an example.
I knew a women here in Taiwan (another teacher from the US) who, when she found out one of our coworkers was gay said, “I think it is more honorable when men don’t talk about that kind of thing.” When I found out she said this, I wanted to go and bitch slap her. Instead, though, I made a point of mentioning my boyfriend in front of her as often as possible. “Jonathan, what did you do this weekend?” “Oh, my bf and I went to…” Etc… 
The sad thing is many of the gay men I meet here in Taiwan – foreigners and Taiwanese alike – seem to hold to that same belief. When confronted by questions of “girlfriends,” “wives”, etc… they say, “It’s my personal life” and refuse to speak about. But, how in the world will your friends, coworkers, family, neighbors, etc… become comfortable with the idea that gay people are just as normal as them, if they don’t “see” the gay people that are around them?
I’m not advocating shouting it from the rooftops, or introducing yourself as “John the gay man” or “Sally the lesbian.” Because, as has been pointed out, being gay is one part of who you are and you don’t want to be known onlly as that. But, on the other hand, why should you hide that part of yourself? If your straight coworkers can put pictures of their loved ones on their desk, talk about their weekend with the in-laws, etc… why can’t you, just because you are gay?
