Jackson proudly noted that '23', which was his father's lucky number as it was the one he wore on his cricket jersey, is special.
"I turned 23 this year which is a very special number," he shared.
Finally, he concluded, "Thankyou everyone for the birthday wishes and I will get back to all of you. I appreciate your kind words," before showing support for the AFL team he and his father loved, "Thankyou, go saints ❤️🤍🖤."
The late Shane's famous friends and peers supported his son in the post's comment section.
Brendan Fevola wrote, "❤️🔥," Shannan Ponton penned, "Happy birthday Jakko. Hope you're all well. 🤙," and finally Candice Warner commented, "Happy Birthday Jacko. ❤️."
On Jackson's official birthday, his mum Simone Callahan shared a series of photos in a touching gallery on her Instagram.
She captioned her slideshow, "Happy Happy Birthday Jackson! Wishing you joy today, and always. Keep being You because your kindness & caring nature is beautiful and I'm so proud of you!! Your courage and strength is extraordinary."
WATCH: Simone's tribute to her only son, Jackson, for his 23rd birthday.
Simone also shared a bittersweet throwback of her former husband holding her son when he was a child.
"We love you so much. Dad would be so proud of the man you are becoming," she gushed.
Jackson's sister Brooke also shared a birthday message on Instagram with family photos.
"Happy 23 Birthday to the best brother anyone could ask for, you are one of the strongest and most incredible humans on this earth and I'm so lucky to call you my brother, your day 🤍🎈⭐️⭐️🎈🤍❤️🍰," she wrote.
This story originally appeared on our sister site, Now To Love.