Becoming a mom was life-changing—that's nothing new. What I didn't expect was for my son to change my father's life so drastically from the second he was born and he turned into a grandpa. It's been life-changing for all of us.

My dad has always been a character. I remember when I was little that he was the life of the party. He would drag me to the dance floor to show off our perfectly coordinated father-daughter moves and he would stay up late listening to music or watching movies.

My parents had tons of friends who were constantly parading our place keeping it loud and alive. And we traveled— we traveled so much as a family that I think I've seen most of the world before my adult years even started.

Then he grew older, and so did I. I moved far away, started a new life, got a job that kept me busy, made new friends and fell in love. And so the adventures with my parents became fewer and more spread out. My dad became slower and he rarely stays up late now. Living in New York made me grow colder and age did the same for him.

My parents struggled with infertility for more than a decade until my mom was finally pregnant with me. She was unable to get pregnant again so I was an only child. They always wanted a big family with children running around the house, but life had a different plan for them.

I spent most of my adult years telling my parents to not hold their breath for grandchildren because my career was more important.

But then I got pregnant.

The day I told my parents I was expecting a boy I could already feel how this baby was going to change my father's life. After all these years, he was finally going to be able to spoil someone even more than he spoiled me. But it was even better, because—in the very old school way of thinking he has—my father was going to be able to teach his grandson all the "boy stuff" he was not able to teach me.

He immediately bought his unborn grandson a soccer shirt that will probably fit him when he turns 14 years old. That's how excited my dad was about the future.

Seeing him interact with my son is pure magic.

At first, it was rocky—he had forgotten how to hold babies and was worried he would hurt him. He would ask how long a newborn would sleep during the day because all he wanted to do was make funny faces and stare at this tiny human. But with every day that went by, my dad's love for my son grew more and more. When my son became mobile, my dad would follow him with a close eye making sure that he wouldn't get into any trouble, shooing away our family cats and dogs that wanted to come to sniff and lick their new play buddy.

Now that he's a full-on toddler, they have so much fun together. I see my dad do the same things I remember him doing with me as a kid, like pretend horse riding on his knees or hiding behind a door for me to come find him.

Whenever we go somewhere all together as a big family, my dad makes sure that everyone knows he is his favorite grandson (yes, he is the only grandson, but still the favorite!). He also asks people if my son looks like him because he is convinced they are identical twins separated by many many years (to his defense, my son looks a lot like me and I look a lot like my dad so he might be onto something).

Recently, we were having dinner and I was trying to have a conversation with my dad, but he was not listening because my son was playing peek-a-boo behind a napkin.

"Hello? Can someone pay attention to me and not my son?" I asked, frustrated.

My dad laughed out loud. "Life is not about you anymore, it's all about him for me."

And that's when it hit me. The cool dad he used to be with me, the funny, playing, chasing dad I remembered is not gone, he was just replaced by a funnier, more loving grandfather. And I couldn't ask for anything better for my son to experience.

I hope my dad gets many years to chase after his grandson because, selfishly, I get to see him in his best role yet—as Grandpa.