Unfortunately, in many states, your vote is completely useless. One vote doesn't make a difference because elections are rarely won by one vote. The electoral college makes useless voting even more common. See how the Presidential candidates didn't visit 40 of the 50 states during the final few days.
If you get into a car accident on the way home from the polls, you will or should regret voting. If there is a patient in the ER and you sneak off to vote and the patient complains to the chair, that's another reason to regret voting.
On the other hand, I risked a car accident or other disaster and did vote.
