Midterm elections are always lower-turnout affairs, but 2014 was exceptional: A meager 36 percent of eligible voters cast ballots, 5 points lower than in 2010 and the worst turnout rate since 1942, according to the U.S. Elections Project. So, why did so few Americans vote last year? The Census Bureau asked just that to people who chose not to cast ballots.

Being "too busy" tops the list of excuses reasons, followed by general lack of interest, illness, being out of town, simply forgetting, and disliking the candidates or the issues. Few people blamed registration issues, inconvenience, transportation issues or bad weather.

While Americans reasons for not voting seem reasonable enough, they don't really explain exactly what made 2014 unique. The same Census survey in 2010 found non-voters gave almost the exact same reasons for casting ballots. In non-voters' minds at least, the reasons for not casting ballots were hardly exceptional despite the historically low turnout.

What is striking is that peoples' reasons for not turning out in 2014 are some of the same challenges governments and political campaigns are working to help voters overcome. A steady rise in the availability of early, absentee or mail voting would seem to help the nearly half of non-voters who cited reasons like being busy, out of town or simply forgetting.

Many people took advantage of those options, with over 3 in 10 voters in 2014 saying they cast ballots that way in the Census survey. But that seems odd; if early voting is becoming easier and more popular, why is turnout dropping with non-voters citing similar reasons of busyness and convenience?

Here's a simpler way to explain low turnout in 2014: Americans can overcome most of their reasons for not voting if they are actually motivated enough. But interest in the 2014 election was lower than previous years, according to Washington Post-ABC News polling. In a late October poll, 68 percent of registered voters said they were following congressional elections "very" or "somewhat" closely," down from 76 percent in 2010 and 78 percent in 2006. In 2012, fully 99 percent of voters were following the presidential election at least somewhat closely, and the share following "very closely" was more than double that of the midterm election (66 percent versus 25 percent).

When an election is extremely interesting and competitive, people find ways to take time from their busy lives and vote, and campaigns spend extra money to reach them. The low 2014 turnout may have just been too boring to bother with.