On Thursday morning, the reality star's new lifestyle website, Poosh, shared a video for their founder's special day. In the clip, Kourtney's friends and family told their "wildest" Kourtney anecdotes. From breaking into the homes of ex-boyfriends to breast pumping before a girl's night out, Kourtney's loved ones held nothing back when it came to the best memories of they've shared with the E! star.
Momager Kris Jenner was up first and shared a hilarious story about her first born. "One of the craziest stories that I remember about Kourtney was when she was two years old," she began. "She fell asleep on the school bus, going to school and the bus driver didn't see her sleeping on the bench because she was so tiny and petite."
She continued, "And the bus driver dropped off all the kids, Kourtney was still sleeping. He locked up the bus and went out to breakfast and that was pretty traumatizing."
Kendall Jenner said her wildest memory was when she was a little girl. "My wildest memory of Kourtney is probably just when we were younger, she would babysit Kylie and I a lot," she recalled. "She would pick us up in her white BMW and she would just drive us really fast and take us to her house where her and her boyfriend lived and she would just make us junk food all day long and let us play video games."
Kylie also chimed in with her favorite memory. "When I was about seven and we went to Disney World and we got into a huge, huge fight -- me and Kourtney -- over these Tinkerbell pajamas that I wanted and she wouldn't let me have them."
Kim, however, said she didn't have the fondest memories with Kourtney as a child. "I just remember having like the saddest memories because Kourtney was so mean to me all the time," she recalled. "She was always finding a way to pick on me or make fun of me."
"A funny little example is when we were in Palm Springs -- that's where our grandparents lived for the summertimes -- and we would go and stay with them," Kim said. "And so they had a golf cart and we would ride the golf cart or I would beg to ride the golf cart. But Kourtney would always take her friends and my friends, turn my friends against me and I was never allowed on the golf cart. So I had to rollerblade and I would always follow them on the golf cart and she would take like fruits, because there's all these fruit trees there. So she'd take grapefruit and oranges and throw it at me and try to get me to fall and laugh with everyone."
The KKW founder also recalled another anecdote about a time when a drunk Kourtney peed in the lobby of a hotel in Miami because she didn't want to wait for the restroom. "Thanks to Kourtney I never got into drugs or drinking," Kim joked.
Khloe, on the other hand, was slightly more hesitant to reveal secrets from her past adventures with Kourtney. "Kourt and I have a ton of great memories," she said. "I'm trying to think of a crazy one that she would want me to share. I mean there's just a lot -- from her breaking into boyfriends'houses to scratching a couple people's faces."
"I think that's the thing I love most about Kourtney is that when she wants to do something, she like is the most fun and she gives it her all," Khloe added. "She's just fun and silly and she goes with the flow."
Kylie also piped up again to tell Kourtney that she looks even younger than she does.
Watch the video below for more fun stories about the Poosh founder, including close Kardashian family friend, Simon Huck, sharing a funny tale of the time he was on a jet with Kourtney and how she reacted when it had engine problems.
HBD @kourtneykardash Can't believe the life we have lived! It's such a dream to go through it all w having a sister like u by our side! You're such an amazing mom &friend! Can't wait to celebrate u tonite! I love you beyond what you could imagine pic.twitter.com/6lSDlvrvXZ