CatDog (1998)

S1E15 Fistful of Mail!

Dog encounters a paperboy who outpaces him, sparking his frustration. Determined to improve, he trains daily to boost his speed. However, he eventually comes to the disappointing conclusion that he may never catch up. To make matters worse, the former mailmen ridicule him for his lack of speed. In a moment of clarity, Dog understands that the mailman has been fast since his youth, but in an unexpected twist, he manages to surpass the mailman’s speed, proving that perseverance can lead to success.