HOLDEN, Maine — The kindness of a young stranger who decided to give away his allowance to celebrate Christmas touched the heart of one man he assisted.

“Nothing like that has ever happened to me before,” Joseph Gunn, a social studies teacher at Ellsworth High School, said Thursday. “That was pretty cool.”

Gunn, who lives on Church Road in Holden with his wife, Debra, said that he noticed a red cellophane envelope under his windshield wiper as he was leaving the Brewer Hannaford on Dec. 23 carrying Christmas dinner in shopping bags. He discovered a child’s hand-written note inside.

“My Mom asked me to think of a random act of kindness,” the note said. “I decided to give up a month’s worth of allowance to buy gas cards for strangers. It isn’t much but I hope you pass it on. Merry Christmas!”

The note was accompanied by a $5 gift card.

Gunn, a veteran teacher with 32 years of experience, guessed the card came from a local boy.

“I’m a schoolteacher and I’m thinking it’s a boy — [age] 8 or 9 tops,” he said. “That’s based on the handwriting.”

The Holden resident was so moved by the gesture of kindness that he submitted a letter to the editor of the Bangor Daily News, hoping the do-gooder will see his message of thanks.

“Well, my young friend, you and your mom made my holiday!” he wrote.

Gunn also issued a special message to the card writer’s mother.

“Mom, you are teaching your child the selfless act of giving, and with passing on values like that, I am truly [appreciative] of this holiday season,” his letter to the editor states. “And yes, my young friend, I will be passing it on.”

Exactly how he will pass it on is something Gunn said he hasn’t figured out yet.

“I’m still working on it,” he said.