George Clooney's friends credit Stacy Keibler for helping him to get over his fear of commitment.
The 鈥淕ravity鈥� star, who proposed to British lawyer Amal Alamuddin on April 22 after just a few months of dating, amicably split from the former wrestler last July after two years together but his pals believe she taught him a lot about relationships.
A source told PEOPLE magazine: "She was one of the first women he's dated who had her own life. She was sweet and had a very good heart, and he was attracted to that."
The insider explained that George was "relieved" when he started dating the 34-year-old blonde beauty because "he didn't seem completely happy" after ending his two-year relationship with Italian presenter Elisabetta Canalis in 2011.
And after his split from Stacy, the actor, who previously swore off marriage following his divorce from Talia Balsam in 1993, "was calmer and seemed more open."
The insider added: "He was in a place to meet the woman he would be with for the rest of his life.
"He has matured and evolved, and he has found someone who can keep up with him.
"He respects that she is not remotely involved in his world. She seems to have no interest in a Hollywood life in the spotlight."
Stacy has also moved on and is expecting her first child with her new husband, Jared Pobre, later this year.
Meanwhile, George, 52, was an instant hit with Amal's family and they weren't surprised by their whirlwind engagement.
A friend said: "(They) weren't surprised that this is such a lightning relationship. They found George very easy to get along with, cool. They felt at ease with him immediately."
The couple is in "no rush" to tie the knot and neither of them "has ever talked about wanting kids," but a family member said they are toying with the idea of a September wedding.
