Obviously, he has been flooded with good wishes from his friends and fans since morning.
What caught our eye, however, was Hrithik Roshan's tweet.
Karan Johar? Superman? Now, that definitely perked up our ears.
A little digging on our part and we found the dirt on KJo. So turns out, during their childhood days, Karan had shown up at a theme party dressed as Superman. What's wrong with that?
Umm, turns out, it wasn't a theme party at all. Hrithik, Abhishek, Uday Chopra and others had turned up in casual clothes and couldn't stop laughing at KJo's Superman avatar.
Clearly, that has become their favourite childhood memory. The actors had even discussed this previously on Twitter in 2012.
Karan as Superman? That's something we find hard to imagine. What say you?