This is because taken at face value the concept seems silly. why would you celebrate being gay? That is like celebrating having brown eyes, or blonde hair, or black skin. It is just something you are born with.
Later when I got older I had a change of thought in many regards on this issue.
Firstly why not celebrate every aspect of who you are even if it does seem a little silly to others? I mean if we can celebrate our cultures and our religions why not our sexual orientations?
Secondly what we are really celebrating in pride parades is not being gay necessarily
... it is about what we as gay people have done throughout history with the great gift of being gay that was bestowed upon us at birth!
It is about celebrating our victories, our achievements, and our various arts and skills that we bring to the world; the beauty we serve... and that we enhance life with!
What we are celebrating is who we are inside; celebrating our great capacity to love! As well as having an attitude of thanksgiving... for our unstoppable Spirit as gay people or people in the Queer Community (L.G.B.T.Q. people) that never seems to die! It keeps getting up every time someone tries to knock it down, and it refuses to be ignored and go away.
We will not disappear. We will overcome! We will be citizens...full citizens of this planet! We will take our place amongst our fellow men and women in every nation on this earth! I think that is worth celebrating don't you?