Dave Coulier becomes a grandfather despite cancer diagnosis (exclusive)

Dave Coulier enjoys the little moments of his cancer diagnosis.

In an exclusive interview with PEOPLE, the Full house The 65-year-old actor opens up about how he relies on family and friends after learning in October that he had stage 3 non-Hodgkin’s lymphoma.

While he notes that his diagnosis was “a really quick rollercoaster,” he adds that his wife Melissa Bring and son Luc were his biggest motivations as he underwent chemotherapy, especially after seeing them responded to his cancer news.

“I looked at the impact those words had [my wife] and I thought, ‘You know what? I will be strong all the time, not just for myself but for her too,” he says.

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He adds that it was particularly “hard” to tell his 33-year-old son Luc as he is currently expecting his first baby, a boy, with his wife Alex, making Coulier a grandpa for the first time.

With his first grandchild due in March, a month after Coulier is expected to finish chemotherapy, he notes that there is “a lot to look forward to” in the coming months, including introducing his future grandson to everyone his favorite hobbies, including hockey and airplanes.

“You’re talking about an apple that doesn’t fall far from the tree. My son Luc plays hockey three days a week. I took him flying when he was a baby, and now he’s a pilot for FedEx,” he says of his son, whom he shares with ex-wife Jayne Modean.

Coulier says that in the midst of his battle with cancer, he gained a new perspective on life.

“We all have choices in life,” he states. “You can laugh in difficult times and try to see the glass as half full, or you can go in the opposite direction, which doesn’t really help. And so I made the decision – the decision was kind of made for me – you’re going to get through this, but you’re also going to help some other people along the way.”

Although he was “stunned” by his cancer diagnosis, he said that ultimately he was “remarkably calm, whatever the outcome.”

“I don’t know how to explain it, but there was an inner calm through it all,” he says, noting that he was inspired by his own family’s experiences with cancer, including his late mother, sister and niece.

“They really instilled that in me and inspired me in a way because they were great at what they went through, and I was just like, ‘I’m okay with that too.’ “I’ve had an incredible life on a journey with incredible people around me, and I’m doing well.” It definitely changes your perspective. All the clichés start like “Don’t worry about the little things” and “The glass is half full” and trickle down to the extreme and shape who you really are.”