Dwayne Johnson is sharing a bit of insight into why he's such a proud father.
The "Jungle Cruise" actor, 51, took to Instagram on Thursday to share a photo with one of his daughters to mark a special moment in her horseback riding career.
MORE: Dwayne Johnson talks fatherhood and what 'Black Adam' means to him"Her first tack trunk," he wrote in the caption. "As many of you know, it's a big and cool deal for young riders."
Johnson continued, "Super proud of her discipline, commitment and focus."
In the photo, the action star is standing behind his little girl, who is decked out in a helmet and riding boots, standing in front of her new tack trunk, which holds horseback riding equipment.
MORE: Dwayne Johnson shares funny video of daughters giving him 'a makeover'Johnson is a dad to daughter Simone, 22, whom he shares with ex-wife Dany Garcia, and daughters Jasmine, 7, and Tiana, 5, whom he shares with wife Lauren Hashian.