Question

irony of my lost dollar

Answer 1

There are a few ironical strains in the story.
1. Todd borrows a dollar not quite out of need, but more so out of convenience. He did not need the dollar to buy anything important. Instead, he used it to pay the cab driver.
2. Throughout the story, the speaker feels awful about Todd not returning the dollar. It bothers him quite a bit, but it is only towards the end does he realise that he might have done the same to many others!
3. The plot begins with one dollar and ends with the speaker talking in terms of a large scale campaign!