"I'll be back" — true for The Terminator, not so true of certain celebrities you swore were still in the business.

While stars like Maggie Smith, Betty White and Cecily Tyson have devoted their entire lives to the craft of acting, others — musicians and thespians among them — have called it quits...sometimes, with so little notice, even their most avowed fans have been caught off-guard.

Yup, between Cameron Diaz, Elton John and Portia de Rossi, the collection of celebrities you didn't realize are retired is shocking, and continues to expand. After all, if Anita Baker can walk away from Hollywood, nothing is a sure thing.

(Thankfully, some like Kevin Jonas ultimately decide to come back to the biz, but our hearts simply can't handle additional stress!)

Check out 25 celebrities you didn't realize are retired in the gallery below.