In Which I Realize I Am Old

A friend of my mother's posted a picture of her on facebook today.  My mom is in the center of the picture, with two of her friends on either side of her.  She is pretty, smiling, looking very happy.  When I saw it I thought "oh, she looks so pretty for her age!"  I saw the year the picture was dated from, I would've been 17 when it was taken.  I remember very clearly what Mom was like at that time.  She was, um,  how can I say this delicately?  She was...old. 
Then it occurred to me to do the math.  Granted, it took me quite awhile, and all my fingers and toes, but I finally got it figured up.  In that picture, my mom was....the age that I am now.
This just really freaks me out.  I mean, I still haven't decided what I wanna be when I grow up!  I'm not old!  Heck, I'm still immature!  How can this possibly have happened?
I've seen the changes coming.  Lately, I can't stand to listen to the radio.  The songs don't even sound like music, they sound like noise.  Who have you ever heard utter that phrase who wasn't old?! 
I forget things, usually mid-sentence.  The other day while cooking, I asked Brenna to get me the lid to a certain pot.  I said "It's the one with no...with no...um..."  Brenna said "Handle?" and looked at me with a mixture of pity and derision.
When I sit for a long time, and stand up suddenly to walk, my legs do not work.  When I wake up in the morning, I have bags under my eyes.  When I say bags, I do not mean like a handbag or a duffle or even carry-on.  I mean LUGGAGE.  
When I bend my knee just the right way, it cracks, loudly.   When I shift my weight on my hips, my right hip pops.  Loudly.  Both of these things have happened before when it was quiet and I'm SURE people around me think I farted. 
I can no longer answer the door, check the mail, etc... without wearing a bra.  Gravity has made it's mark.
I have trouble with my feet and now prefer to wear flats.  I have to get my kids to show me how to work any current technology, cuz I don't know how.  I have to buy the special dye for gray hair for it to really cover anymore, and I have to pencil in a portion of my eyebrows from years of over-tweezing.  I use phrases like "hurts like the dickens!"  Which makes my teenager laugh until she cries cuz it sounds so old fashioned.  And my husband has a pacemaker, for goodness sake! 
That's it, I may as well throw in the towel.  I'm admitting it here and now.  I am old.  Now I'm gonna go wash off my eyebrows and go cry myself to sleep in my... my.... um, that soft place.