A Different Reality
It is a well known fact that society, and humanity in general, have the way of underestimating someone down to an art. Ironically, it is often the people who are overlooked and never given a second glance that make the most impact on things. They are judged by society as too ordinary or average to make any sort of a difference in our world. Take Arthur for example. He was a scrawny stick of a boy who did not amount to much. Fate of course had other plans. Many know the story. The boy grew up to become a legendary king and a wise ruler. But if you had told anyone who knew Arthur that one day the lad would be one of the most renowned kings of all time, they would have burst out laughing and thought you were touched in the head.
It just goes to show that humans never do learn much from past examples. Whole civilizations can be effected by one person, one supposedly insignificant person that everyone overlooked.
In this case it happens to be two, a couple who prided themselves on their normality and perfectly dull life. They would soon have to make a choice that would impact the balance of things far greater than they could ever imagine. They were underestimated, however, by a powerful wizard on whom a boy's and in turn the world's fate lay. The wizard was so sure that the couple would do what he expected, he neglected the slight chance that everything would not go as planned.
A single action would twist 'what if' into reality. For the Dursleys, it was a quick and easy way to get what they loathed out of their lives as fast as possible. For the Wizarding World, the future would soon be drastically rearranged. But most importantly, for Harry Potter, their decision would change his entire life.