The 34-year-old Narcos star recently opened up about the day Olsen broke up with him - which also happened to be the day death took a very good friend from him.
"On the same day that my best friend died, I got a call from my girl to tell me it was over," Holbrook admits in the 14th issue of Man of the World magazine.
#ICYMI: Boyd and Elizabeth started dating in September 2012 after costarring with one another in the 2014 indie flick Very Good Girls. Rumors insisted they had gotten engaged in or around March 2014, but neither actor or their reps would ever confirm that news. As of this past January, it appeared the couple had gone their separate ways after Elizabeth stopped wearing her engagement ring and gossip cops claimed Olsen had started dating her Avengers comrade-in-arms, Tom Hiddleston.
Boyd's aforementioned friend was photographer David Armstrong. He died at 60-years-old after a fight with liver cancer.
"David was the first person in my life to encourage me," admits the Gone Girl actor. "He told me to do everything I wanted to do. No one had ever told me that before. He was a very important figure in my life. Important figure is not even close to what he was."
And although it seems as if Holbrook still thinks about his ex-fiance, Elizabeth has spent the last year or so defending herself from the public's prying eyes.
"We happened to be at a restaurant at a wrong time having dinner. We all go out to dinner." Olsen, 26, said of her alleged relationship with Hiddleston in an interview this past September. "Apparently, I'm dating Chris Evans, and apparently, I've dated Jeremy Renner, so...I don't react to it...People can think what they want to think."