Thomas Rhett is the first to admit that his household is "utter chaos," but he wouldn't have it any other way.

"It's amazing how fast they grow," the country superstar, 28, tells PEOPLE of his daughters Ada James, who turned 1 Sunday, and Willa Gray, 2½.

"Before you become a dad, you talk to other dads and moms and everybody is like, ‘Dude, soak it in because it's going to go fast,' " he added. "And somebody told me this quote: ‘The days are long and the years are short.' I don't think you fully understand what that means until you have kids."

Thomas Rhett/Instagram
Thomas Rhett/Instagram

The "Die a Happy Man" singer has been vocal about his children and his loving marriage to wife Lauren Akins. He often tells their personal stories through his own music, such as his song "Life Changes," where he sings about becoming a parent of two children within three months after adopting Willa Gray from Uganda in May 2017.

"It's not like there ever is a perfect time to have kids, or a perfect time to put out a record," Thomas Rhett told PEOPLE in a September 2017 feature. "We just happen to be doing both at the exact same time! We keep going back to ‘Take it one day at a time.' "

Thomas Rhett/Instagram

And that's exactly what they've been doing. From taking family vacations to Walt Disney World and Chicago to relaxing at their Nashville, Tennessee, home and accompanying Thomas Rhett to shows on tour, his kids are reaching milestones quicker than he ever could have imagined.

"Ada is walking. Willa Gray is having full-on conversations with me," Thomas Rhett says. "She's smarter than I am. It's only going to continue to get worse, but it's been such a life-changing experience in all the best ways possible."

He adds, "I never thought that I could love anything more than my wife — not that I love my kids more than my wife — it's an equal love, but it's just a different kind of love and it's just been such a crazy last couple of years."

This Story Originally Appeared On People