Well, at my riding lesson today I had SUCH a blond moment (and I can say that because at the moment I'm technically a blond).
I have a saddle on trial that I was riding in, so I got all tacked up; mattes pad, thinline, square pad, girth, martingale, bridle, fly mask, nose sock (my horse is speshul), front boots, polos. I mean, I remembered eveything. Or so I thought...
I get halfway out of the barn and my friend says to me; "So, are you riding without stirrups today?" I was like, "No, why?" And she goes "You might want to look at your saddle then."
Of course, being a test ride saddle, it didn't come with stirrups. And I forgot to borrow some from my instructor. So my wonderful friend let me borrow hers (she wasn't riding with me). My favorite part of the whole thing was her little comment at the end. "I've never let someone borrow my stirrups before."
I'm sure I'm not the only one whose done something really silly like that. And don't just say you forgot your helmet, because everyone has done that at least once! Unless you don't wear a helmet anyway, haha ;)