Then again:
Europe is playing up again and is in recession.
Consumer confidence is down.
Labor participation is still at a 10-year (or more) low.
Sequester cuts are starting to pinch. Quite a few people I know are being furloughed and are cutting back on spending.
Markets have gone up too far too fast. A 5-10% correction is probable given an appropriate trigger (or manipulation). Happened basically every year since 2009.