Today is Jack Gilinksy's 19th birthday, and we can hardly believe it! In honor of how much he's grown up over the years, we're celebrating his longtime friendship with his Jack & Jack bandmate, Jack Johnson.
The two met on the first day of kindergarten, and they're pretty much the epitome of friend goals. Though you know what they look like now, you'll totally be shocked to see them grow up through the years.
Seriously, prepare to get emotional.
From their fetus pics to their middle school days, click through to see more throwback photos of the besties. And don't forget to wish Jack a happy birthday in the comments!