One of the greatest sports movies of our time exists because of a dog, or at least that’s what Sylvester Stallone claims in one of two revealing Throwback Thursday Instagram posts.

On Thursday, the actor, 70, posted a pair of back-to-back shots from his rough pre-fame days that feature himself and his old dog Butkus. In the two #TBT photos, Stallone opens about the profound effect Butkus had on his life.

“When I was 26, totally broke, going nowhere VERY fast, owned two pair of pants that barely fit, shoes that had holes in them and dreams of being successful were as far away as the sun … But I had my dog, BUTKUS, my best friend, my confidant, who always laughed at my jokes, and put up with my moods, and was the one living thing that loved me for who I was!” Stallone wrote along with the first photo, which shows the actor leaning down to hug his furry friend. 

The following photo, which features Butkus as a tiny puppy sitting on Stallone’s lap, dives deeper into the relationship Stallone and his devoted pet shared.

“There was not much to do except spend time with each other and that’s where I started to learn the craft of screenwriting. Since I never went out, I relied on his companionship, And actually it was his idea to write Rocky, but don’t tell anyone,” he wrote about his days trying to break into the movie business.

In the post, Stallone also admits that there was a time he was so destitute and hungry that he had to sell Butkus for $40. Luckily, this sad story of parted friends has a happy ending. After making it big with Rocky, Stallone tracked down the person he sold Butkus to and bought him back –  for a slightly inflated price.

“The new owner knew I was desperate, and charged me $15,000,” Stallone shared with the photo. “He was worth every penny!”