Love Island host Flack took her own life on February 15, 2020, aged 40.
Flack and Murs, 38, shared a close friendship after the pair worked on The Xtra Factor together between 2011 and 2015.
Murs described the experience of losing the late star as “traumatic” and still hard to accept as he spoke to Heart Bingo’s Blog.
He said: “It was such a traumatic experience. It was and still is hard to deal with. She was a good friend and she’ll be a part of my life forever.
“But I try not focus on the sadness and just focus on the positives. I believe Caroline is in better place now. I choose to focus on the memories of our friendship and that I am glad I got to know her.
“I do not want to spend too much time focusing on the negatives. I have just lived my life like that since I was a young kid. It is how I have built my career really. I want people to be happy and I want to make them laugh.”
Murs has continued to champion Flack following her death. Last year, he joined Flack’s family on a trek in honour of her, raising £28,000 for suicide prevention charity Samaritans.
Murs also performed at the first Flackstock festival in June, which was created by Flack’s friends, along with her mum Caroline and sister Jody to celebrate the memory of the star.
Murs mentioned his signature positive attitude as a way of helping him deal with the toughest moments in his life.
He continued: “I’m lucky. I have a good family and support system.
“It is just a part of my personality. I love living a positive life. I simply feel good when I’m being nice to people. I’m just nice and respectful to people. That is what my parents always taught me, to be respectful to everyone.
“There have been times in my life which have been difficult. Whenever I’m in a negative situation, I just try and focus on that one positive thing which makes me happy.
“Some people are not able to do that. Which is fair enough, as I said, I have been lucky in my life. Even the moments in my life, and there have been a few, I focus on the good.”