What a difference two years have made for the son of actor John Stamos and his wife, Caitlyn McHugh, who took to Instagram to show pictures of not-so-little William ‘Billy’ Christopher who had been born six weeks early.

At the time, his parents were worried as they shared with PEOPLE that it took time to adjust. Caitlyn said: “He was very, very small…fragile, little. Every time [he] fell asleep, you’re like, ‘Please wake up.’ (We were) constantly checking to make sure he was still breathing.”

Stamos found himself smitten, doting on the little boy bundle of joy on social media. The star of the former show Fuller House consistently shares cute images of him and the toddler to the delight of fans, noted Amo Mama in a report.

Stamos earned a degree in arts and literature, starting acting at 19 in TV commercials before landing his first role in the 1982 soap opera, General Hospital, and later winning his first Emmy Awards nomination, Young Artist Awards in the category of Outstanding Supporting Actor in a Drama Series, propelling himself into a household name with adoring fans.