It's crazy to believe it has been 18 years since That '70s Show premiere, taking viewers inside Eric Forman's basement!

Since the first episode of the popular FOX series, fans felt welcomed into the circle of trust —and thanks to reruns we can still catch up with the bell-bottom-clad gang!

Happy birthday That '70s Show! See how much Kelso, Fez and the rest of the cast has changed in the slideshow above!