Most things driving people to sell don't get undone quickly, says Jim Cramer

It happened again. Investors egged on by negative commentators in their media echo chamber drowned in a wave of pessimism last week. And you know what.They missed one of the best days of the year today. People just can't seem to process the most important three words in the investing lexicon. Stay the course.Nobody wants to stand pat when they think they can get out and then jump right back in. That's incredibly difficult, especially when you get an indicator that showed less inflation than we thought. Like ...