Feeling a little unprepared for the premiere of The Big Bang Theory season 8? Brush up on your knowledge with our recap of what happened last season!

Leonard and Penny were a roller coaster…

After a happy reunion following Leonard’s long expedition in the North Sea, Leonard and Penny hit an unusual snag. Over Thanksgiving, the gang learned that Penny was actually married to the ridiculous Zack, upsetting Leonard. But after a hasty divorce in Mrs. Wolowitz’s dining room, the two reconciled.

Trouble reared again when Penny fell into an existential crisis after being cut from an episode of NCIS. Leonard’s attempts at being supportive culminated in Penny drunkenly proposing marriage, which he nervously turned down.

…but they pulled out a win!

Infuriated, Penny quit her job at the Cheesecake Factory to pursue acting full-time. Leonard was initially skeptical, since Penny was basically broke. But Dr. Hofstadter proved his devotion to Penny by buying her a car so she would not have to return to waitressing.

After a disastrous, but well-intentioned stint on the set of Serial Apist II, a frustrated and humiliated Penny decided to make a smart decision and marry Leonard. Though, like so often do, the pair got the proposal off on the wrong foot, they wound up touchingly putting the long-awaited ring on it.

Amy and Sheldon went some-steam ahead

The indestructible ShAmy continued to beat the odds last season. Sheldon was forced to adjust to continued proximity at when Amy began working on an experiment at Caltech. Later on, Amy realized that Sheldon really does care for her – he has a picture of her as his screensaver!

The pair had an especially big moment on Valentine’s Day. A romantic Valentine’s Day train ride sparked a fight (as Amy was interested in the “romantic” part, and Sheldon was fixated on the “train” side of the experience.) But an angry kiss turned unexpectedly passionate, opening Sheldon’s mind to the possibility that being physical with Amy might be something he could want.

Howard and Bernadette took on weight

Early in the season, Bernadette got exposed to a raccoon virus on her and Howard’s anniversary. But it turned out fine, because then this adorableness happened:

After realizing that neither Howard nor Bernadette was interested in having a perfect spouse (ie, Raj) the married couple took on the exceptional burden of caring for Mrs. Wolowitz, who had broken her leg. The search for a caretaker seemed impossible – until a lucky fire in Stewart’s comic book store left the poor schlub desperate for work.

With Stewart and Mrs. W getting on famously, it seems like the Wolowitz Family Problem may finally have resolved itself!

Raj got moves, more or less

Now able to speak to women while sober, Raj tried to find love on a dating website with Stewart. Eventually finding someone he was interested in, Raj hired Amy to play Cyrano DeBergerac for him with a girl named Emily.

Though things got off to a rocky start (especially once Lucy came briefly back into the picture) Emily is hard to scare, and Raj broke his long-standing sexless dry spell with her.

Sheldon made a few discoveries

Sheldon successfully discovered a stable superheavy element, possibly his crowning achievement as a physicist. Unfortunately, his glee soured when he realizes that he came to the answer through a mistake. Leonard disproved Sheldon’s theory entirely, which further upset the bundle of contradictions that is Sheldon Cooper.

Further disillusioned by advancements in the study of the (actual) big bang theory, Sheldon tried to break up with string theory. However, he is unsuccessful at finding a new field of study and infuriated when Caltech insisted he continue working on string theory.

Even a ghostly visitation by the now-deceased Professor Proton (sniff) couldn’t fully bring Sheldon peace; at the end of the season, he hopped on a train at the end of the season to ride out his issues.

The Big Bang Theory season 8, episode 1, “The Locomotive Interruption,” and episode 2, “The Junior Professor Solution,” will premiere on Monday, Sept. 22 at 8:00 p.m. on CBS.

Are you psyched for the return of ‘The Big Bang Theory’?