You love whom you love – unless fundamental differences make the relationship just too complicated to maintain.
At least that's the reason being given behind John Mayer and Katy Perry's split, according to a source close to Mayer.
"They're two very strong-willed people," the source tells PEOPLE. "Despite caring about each other very much and wanting to make it work, they are, at their core, quite different."
Among those differences, says one industry insider, is their age gap. At 29, Perry is still very much eager to go out and have a good time partying, and the insider says it could get to be too much for Mayer, 36.
"At times they seemed really happy together and in love, and other times he seemed like he just wanted to get away from all the parties and go home. I can't say I always blamed him," the insider says.
Perry's work schedule may have also been a factor. Having just embarked on her Prismatic World Tour, the insider says Perry knew it would have been too difficult to maintain the relationship while she was gone. "She's a smart girl. She knows no relationship can survive that kind of distance and strain, and she's not going to slow down now when she's at the top of her game."
Mayer seemed to confirm this in December, telling ABC News in December, "Katy is a superstar for a reason."
Perry, who has already played Prismatic shows in Japan and is now in Australia, appeared on the Australian TV show Sunrise yesterday, where she was in a fun mood, and didn't seem to be mourning the split too deeply. When asked if she had a boyfriend, she quickly replied, "All of my fans are my boyfriends."
Meanwhile, Mayer spent the weekend in L.A., hobnobbing with celebs like Kellan Lutz and Zooey Deschanel at an Oscars party at the Sunset Tower Hotel.
"He chatted with Anna Faris and a few guests while drinking Grey Goose and tonics," says an onlooker. "He didn't take any pictures, but seemed to be in a friendly mood."