Four-year-old Carson Knight has been obsessed with UPS trucks almost his entire life.

The Colorado Spring native was born with a condition that doesn't allow him to drink anything with milk proteins, so he had to have a special formula delivered several times a week.

Over the years, Carson formed a bond with UPS driver Ernest Lagasca, who Carson calls "Mr. Ernie." Lagasca handles the route in Knight's neighborhood, and every time he pulls up Carson heads outside so he can check out his truck.

"When Carson was born he couldn't drink milk or anything with a milk protein in it, so they sent formula," the boy's mom, Karen Kight, told KRDO. "Mr. Ernie would deliver quite a few times to our house."

Carson loves UPS visits so much he has his own special brown uniform to wear.

Mr. Ernie sent Carson's story to UPS's Your Wishes Delivered program, which donates $1 to The Boys and Girls Clubs of America, The Salvation Army or the Toys for Tots Literacy Program for every wish submitted. Occasionally they're able to make some of those wishes come true.

A couple weeks ago, when Lagasca stopped at Carson's house, he had a different kind of package to deliver: a toy UPS truck with some packages that Carson had to deliver to neighbors.

"He's just one of those guys who, to me, is very special and has become a very special role model in Carson's life," Carson's mom. "I'm just so thankful that he is one of the most humble, gracious men that I've met to interact with my young son."

Though Lagasca has moved on to a different route, Carson has kept going, delivery snacks and other special items to his neighbors in his mini UPS truck.

Warning: a box of tissues might be needed before watching the heartwarming video below.

Way to go Mr. Ernie.

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