'The Big Bang Theory': Sheldon Takes a Huge Step Forward in the 200th Episode!

EXCLUSIVE: Jim Parsons on Whether Sheldon Will Have Kids Next on…

'Little People, Big World's Zach Roloff Reflects on Raising Kids…

‘Father of the Bride’s Gloria Estefan & Andy Garcia Reflect on H…

Johnny Depp's First TikTok Is Love Letter to Fans After Defamati…

Zendaya and Andrew Garfield Interview Each Other About Tom Holla…

‘Jurassic World Dominion’: DeWanda Wise on If This Is Really Fra…

‘Moonhaven’ Trailer: Joe Manganiello Stars in the Sci-Fi Thrille…

Amber Heard and Johnny Depp's Infamous Penthouse for Sale in Wak…

'Black Adam' Official Trailer

Penn Badgley on Where ‘You’ Season 4 Will Pick Up (Exclusive)

Johnny Depp's Lawyers Hint He Might Not Take Amber Heard's Payout

Jada Pinkett Smith Talks Oscars Slap, Hopes for Will Smith and C…

Johnny Depp Speaks Out After Victory in Defamation Trial Against…

Here's a First Look at Disney Channel's New Series 'Villains of …

'The Princess' Official Trailer

Prince Harry and Meghan Markle Make Platinum Jubilee Appearance …

Adam Sandler Reveals He 'Popped' His Groin While Filming 'Hustle…

Rachel Brosnahan and ’Marvelous Mrs. Maisel’ Cast Tease Milo Ven…

NeNe Leakes Denies Being ‘Husband Stealer’ After Being Sued by B…
WARNING: We're about to reveal what happened in tonight's 200th episode of The Big Bang Theory. If you do not wish to join in on the festivities, leave now. For everyone else, grab a gift and let's party!
After nine years, 200 episodes, and countless storylines later, The Big Bang Theory has finally given us something brand new to celebrate: Sheldon Cooper's birthday!
During Thursday night's landmark episode, Big Bang answered a question that many fans have always wondered about: why doesn't Sheldon like to celebrate his birthday?
WATCH: Kaley Cuoco Talks 200th Episode of 'Big Bang Theory'
In a heartbreaking reveal, Sheldon explained that every year on his birthday, his twin sister's friends would torture and humiliate him. "When I was six, they told me Batman was coming to my party," Sheldon confessed to Leonard, Penny and Amy. "I waited by the door for hours. The closest thing to Batman that I saw was when a Robin flew into the window."
When Amy expressed her deep desire to throw Sheldon the ultimate birthday party, he was naturally cautious to relive those buried memories, but she eventually won him over.. "You made my last birthday so memorable I wanted to return the favor," Amy said, referring to their big sleepover earlier this season.
WATCH: Mayim Bialik and Johnny Galecki Recreate Their Kiss From 'Blossom'

To celebrate the big occasion, CBS brought back many special guests who have played some of the most beloved characters in the Big Bang universe, including Christine Baranski as Beverly Hofstadter, Sara Gilbert's Leslie Winkle, and Wil Wheaton as his wonderfully sarcastic self.
Not only did our favorite group of beauties and geeks throw Sheldon the perfect birthday bash, they even surprised him with an extra special gift: Batman! That's right, the one and only Adam West was invited to the nerd-tastic event, thus fulfilling Sheldon's long overdue birthday wish.
The Big Bang Theory airs Thursdays at 8 p.m. ET/PT on CBS.
Press play on our video below to get the behind-the-scenes scoop from The Big Bang Theory cast at the 200th episode celebration!