Noah Cyrus and Jimmie Allen's "This Is Us" is ultimately about surviving everything you've been through and creating a better life for yourself on the other side, particularly with the people you love. The title refers to the union that's built when people come together. You're still individuals with your own personalities and quirks, but when you give yourself up to another person — when you become vulnerable enough to let your entire self show — you become a new entity with them.
Allen loved the song when he first heard it and was honored to sing it, per Songfacts. The country star then said, "This song takes me back to the innocence of young love, when you loved hard without fear of getting hurt," before adding, "As you grow older, you realize all the times you messed up and made mistakes and how lucky you are to have them in your life." He reconciled that things will work out when they're meant to, and that's ultimately the true message of the single.
What's particularly sweet is that Allen relates this song to friendships as well. He explained, per (via Taste of Country), "That lyric, 'You were just you and I was just me,' – We were kids and we might have gotten in arguments or fights, but we were trying to figure out who we were."
