Last Saturday morning I sat on a jankety stool at a counter in a San Jose diner with my two eggs over easy, talking to a grey-haired gentleman about how thankful I am for my impending hip surgery.

Hi, I’m Lisa, and I’m 85.

Yesterday I put on a bright orange dress, dabbed on new lipstick, curled my hair and attended a joint replacement class at the hospital where I pre-registered for my surgery. In adorable heels. At least five people, from nurses to PTs, said, “Why are you getting a hip replacement?! You’re so young!”

And boom. All of the sudden, I’m 25. God help me. I’m stuck in this weird space of not-old-but-not-young and I don’t know what to do with myself.

Last night at CVS I bought Miralax (a tip from the nurses for post-surgery) and some zit cream (my anxiety is causing a minor breakout). So I will be happy-dancing in my bathroom this month for two very different reasons. Think “dab” more than “twerk” (I’m not sure my hip will support that kind of booty rockin’), but a healthy digestive system and clear skin are equally good reasons to celebrate at my age.

For months now, I’ve been walking with a not-so-sexy limp. I injured my hip a few years ago lifting weights in the gym with my sexy 24-year-old trainer who knew nothing about training someone over the age of 21 sans jock itch. I shook off the pain at first, but over time it worsened and my body started saying, “Nope. Nope. Nope.” Eventually I found a surgeon who finally asked, “Do you want a new hip?” I said, “Yep.”

Now I’m a week away from singing, “I Am Titanium.”

I’m not kidding. I’m going to play that song when they wheel me into my room after surgery. And when I get up later to stroll the hospital corridor with my walker, I’m going to have a Bruno Mars dance party, whether the ortho nurses like it or not, because I will be sporting a shiny new silver stem with a pretty pink ceramic ball in my pain-free hip joint. If that’s not a reason to sing “Versace on the Floor,” I don’t know what is.

I’m not sure what they’ll do with my old bone. Perhaps give it to me to make soup? Maybe mail it to my ex-trainer. Or maybe I’ll draw a face on my femoral head and call it Wilson.

I do know that I’ve spent this past week thanking it. My hips have carried me through a lot of cool shit, and I owe them much appreciation. Basketball games and track meets in high school. A decade of Jazzercise in my 20s. Three pregnancies with 60-pound weight gains. Endless hours of running around, chasing toddlers. Moving my family from one state to another, then my daughters into their dorm rooms. Hiking dusty California trails with glorious ocean views. I have nothing but gratitude for my old joint.

But I’m ready to welcome the new one. Turns out, chronic pain is not super fun.

Until then, I have a week to stock up on Lean Cuisines and microwave burritos, set up my shower chair, pick out a jazzy walker at the medical supply store and buy my favorite prunes at Trader Joes.

I’m not 85. I’m not 25. I’m somewhere between “I’m going to live forever” and “come visit or I’m cutting you out of my will.” My mortality is showing, to be sure.

But I feel all kinds of alive, and I can’t wait to introduce my new hip to the Dipsea Trail in Muir Woods just north of San Francisco. The views are magnificent. The uphills are butt-burners. And there’s a little diner near Stinson beach with bomb breakfasts. Two eggs, over easy, please. With a side of gratitude.