The Big Bang Theory” Season 8 is about to premiere on CBS on Sept. 22 and will pick up with all of the storylines from the finale—but some fans might need a Season 7 refresher. It’s been a long summer. Here’s what was happening with everyone’s favorite nerds in “The Big Bang Theory” Season 7 finale:

Penny and Leonard’s Engagement: Leonard (Johnny Galecki) finally proposed to Penny (Kaley Cuoco-Sweeting). When he called his mom to tell her the good news, he found out that Sheldon (Jim Parsons) already told his mother. Mrs. Hofstadter (Christine Baranski) wasn’t exactly throwing them an engagement party, but if Sheldon was OK with it, so was she. Penny and Leonard realized that they would have to change their living arrangements once they were married.

Sheldon’s Departure: Sheldon didn’t like the idea of moving out. Amy suggested that he could move in with her, and Sheldon was even more freaked out. He was already dealing with a lot of change throughout the end of "The Big Bang Theory" Season 7. He was coping with the loss of his childhood idol, Professor Proton (Bob Newhart), and the idea that he might have to transfer schools to study inflationary cosmology. He ran off and Leonard and Penny found him at the train station. Sheldon said that there was too much change happening, and that he needed to get away for a while. They let him go, but Amy (Mayim Bialik) wasn’t really thrilled that her boyfriend ditched town without saying goodbye.

Stuart Moved In With Mrs. Wolowitz: Bernadette (Melissa Rauch) and Howard (Simon Helberg) were searching for a full-time caretaker to look after Mrs. Wolowitz. No one lasted more than a day in the position, not even Penny. After the comic book store burned down, Stuart needed a job and moved in with Mrs. Wolowitz. He turned out to do really well in the position and loved taking care of the elderly lady.

Raj Had Sex: Finally. Raj (Kunal Nayyar) and Emily (Laura Spencer) consummated their relationship, and it was pretty much all he could talk about through "The Big Bang Theory" Season 7 finale. The entire group was happy for him, and it even outshined Penny and Leonard’s news. “You guys propose all the time. This never happens!” Bernadette explained.

"The Big Bang Theory" Season 8 will pick up 45 days after Sheldon left. He'll still be traveling when he suddenly calls Leonard to pick him up. Raj and Emily will still be together, and Stuart will still be living with Mrs. Wolowitz. In fact, Howard and Bernadette are a little concerned by Stuart's relationship with the woman. One thing that's not returning for Season 8: the majority of Penny's hair. Check out more "The Big Bang Theory" Season 8 premiere spoilers HERE.

“The Big Bang Theory” Season 8 premieres Monday, Sept. 22, at 8 p.m. ET on CBS with two episodes. Who are you most excited to catch up with in the season premiere? Sound off in the comments section below!