We never know the full scale of how what we do can impact the lives of others.

James Gunn, known most famously as the writer and director of the 2014 film “Guardians of the Galaxy,” was touched by a post a fan recently shared on his Facebook wall.

This month marks one year since the release of “Guardians of the Galaxy,” which prompted Josh Dunlap, from Las Vegas, Nevada, to send Gunn a message concerning Dunlap’s son, Sawyer. Sawyer, 4, lives with a developmental coordination disorder called dyspraxia.

Sawyer connected with the character Groot from the movie, and Dunlap credits the character and the film with helping Sawyer learn to communicate better and eventually enter speech therapy.

See Dunlap’s touching message to Gunn below:

Hi James...This is in response to your recent post about Guardians being released a year ago and the effect it has had... Josh Dunlap on Friday, August 14, 2015

Touched by Dunlap’s words, Gunn shared the message on his Facebook page and said, “I love making movies because of stories like this. Thank you.”

See the Guardians of the Galaxy trailer below: