I'm 26 on the 19th, but I don't feel old. I do have moments that are like "woa, that happened in 2001? DUDE!" or "are you SERIOUS!? Your sister is HOW old? I remember changing her diaper!" to kids that used to be in my mom's day care. One just graduated high school and we had her in our day care when she was only 9-ish O_O.
INSANE how fast time flies.