"I already voted".
You are schmuck.
Sorry, it's true.
Okay, it isn't true, and its harsh.
However, there's no point in voting early unless you are going to be out of the country, or something. Otherwise you are simply gambling that the nominees from any one party will still be on the ballot on election day.
What if Clinton backs out, knowing of some deep evil secret in her email? What if Trump finally gets pushed off the nomination by the Republicans who hate him? What if it turns out that everyone gets uncomfortable email from Anthony Wiener and they therefore decide to depart for a private island in the Caribbean? What if Clinton suddenly decides to retire to a convent, like female powers did in days of old, after coming to the realization that you can't really be for death cradle to grave and still be a Christian? What if the New York Times saw a bad story for Clinton that it couldn't find a way to rationalize as a good news for the Democrats? What if some new European model catches Trump's eye and he decides to remarry next week? What if Trump becomes a Trappist monk this week, having tired of models as spouses?
What if the Cubs win a World Series?
This year anything could happen.