She described the guy as being “big, macho-looking” and in his late 20s, expecting him not to take kindly to sitting beside a small child.
“I was completely wrong, and for that I am so grateful,” she wrote.
“The seatbelt sign remained on, which meant instead of sitting and being comforted on mine or grandpa’s lap, he had to be belted in beside you instead.”
The mum continued the letter by thanking the man for how he dealt with her toddler throughout the flight.
“I didn’t get your name, but thank you so much for grabbing his blanket the numerous times he dropped it, half asleep,” she wrote.
“Thank you for making sure to point your cabin light away from him when he finally did fall asleep.
“Thank you for being kind and engaging him even though you weren’t obligated to do so. Thank you for offering him (and us) candy and gum for his ears.
“Thank you for letting him rest his little tired legs and feet on you. And thank you for offering to get down all of our overhead luggage so he wouldn’t be disturbed.”
She wrote that although her son is generally well behaved and quiet, she was anxious and concerned about how his first flight would go for him, expecting people to be unkind and impatient.
She added: “Thank you for making our flight experience a lesson in compassion and empathy for others. You will make a wonderful father some day if you so choose, love an anxious mother.”
The post had 55,000 likes and 2,600 shares in three days. And the power of social media even managed to find the guy, Aly Hyseni, in the photo.
“A friend of mine recognised me in this post and I was both humbled and touched by the kind words of the woman who wrote it,” he wrote.
“I just want to say, that it was a such pleasure to meet such a loving family. Although he doesn’t show in this picture, the young boy’s grandfather should be the one receiving all this recognition.
“His patience and kindness toward his grandson was heartwarming. At one point, this man held his arm suspended above the armrest for over an hour so that the boy could be comfortable resting his head on it while he slept.
“Actions like this are inspiring and we should all strive to be like this man. Thank you for your kind words.”