"I have learned that mourning someone, mourning, is personal," the "Grease" alum, 67, told Esquire Spain, per excerpts from DailyMail. "Mourning is individual and experiencing your own journey is what can lead to healing."
"This is different from someone else's journey," he continued. "The most important thing you can do to help another when they are in mourning is to allow them to live it and not complicate it with yours. That's my experience."
Kelly died at the age of 57 after her battle with breast cancer. The tragic death followed the 2009 loss of the couple's 16-year-old son Jett, who died after suffering a seizure.
"Life is movement and a journey -- what you leave behind in people, I guess that's your legacy," John explained. "How they interpret my life will be different for each one. And that's fine because that will be me."
"The best thing I do is try to get to that part of life that allows me to enjoy it, and that joy is experiencing dance, music and people."
John and Kelly also shared daughter Ella, 21, and son Ben, nine. The actor told the outlet that his children are his main focus in life.
"I will ensure the future of my children, help them with what they want to do with their lives. It is what I do with Ella now with her films and teaching her to work in the profession. Ben is barely 10 years old. I want to help him evolve because he has his whole life ahead of him."
At the time of Kelly's passing, John shared an emotional message on social media.
"It is with a very heavy heart that I inform you that my beautiful wife Kelly has lost her two-year battle with breast cancer," he wrote on Instagram. "She fought a courageous fight with the love and support of so many."
"My family and I will forever be grateful to her doctors and nurses at MD Anderson Cancer Center, all the medical centers that have helped, as well as her many friends and loved ones who have been by her side," he continued. "Kelly’s love and life will always be remembered."
Ella paid tribute at the time as well, posting, "Anyone who is lucky enough to have known you or to have ever been in your presence will agree that you have a glow and a light that never ceases to shine and that makes anyone around you feel instantly happy."