Where does the time go?

This morning on Facebook I went through the normal routine of sending birthday greetings to my friends who have birthdays today. One of them had an age associated with his little photo that I thought was far too old, so in my message I started to type; "you can't be that old, when we met at the 25th anniversary of Stonewall I thought you were about my age, maybe one or two years older." At that moment it hit me that the 25th anniversary of Stonewall was 18 years ago, and we are quickly approaching the 45th anniversary of said riots. That was the first "big gay" think I ever attended (bear runs notwithstanding), and that was now 18 years ago. Even last night Carl played "Beauty School Dropout" from Grease on the way home which caused me to download the film that we watched last night, and that is a 34 year old film. I remember seeing it in the theaters. Hell I have friends younger than this film. Oy. When did all this time pass? There are days I feel every bit of my 45 years, but most often I don't. It is only when I put it into context of the time that has elapsed since events and milestones such as those listed above that I feel old. Oh, and when I look at my nieces and nephews too.