Credit: Instagram

Please pop in Rod Stewart's "Forever Young" and start weeping, because Isaac Rivera is all grown up. It seems like just a few weeks ago that this Teen Mom 2 kiddo was bursting forth from Kailyn Lowry's womb, and now he's starting his first day of school! Sob, where did the time go?

Credit: Instagram

Isaac's life has been chock-full of changes recently. Not only is he getting his education on, he just moved from Pennsylvania to Delaware, and he's about to be a big brother! Yep, Kailyn's pregnant, and all those pesky hormones are making her super emotional about sending her OG kiddo off to to school.

"Such a busy day tomorrow," she tweeted on November 4. "Isaac's first day of school here! nervous for him! So bittersweet."

Kailyn only got more emotional as time went by, and on the morning of November 5 (aka Isaac's big day!) she tweeted, "Let me gather my thoughts before I lose it all dropping Isaac off at school."

Isaac couldn't be starting his education at a better time. In just a few days his momma will have her hands full taking care of a new bundle of joy, and it'll definitely be helpful having him busy at school all day!

Hopefully this little dude will make tons of new friends and become an expert in the art of ABCs!