Now that the "sell in May and go away" theory didn't play out in May, Jim Cramer is hearing chatter of "lighten up in June before the swoon."

Cramer hates these poetic tidbits. If they didn't rhyme, no one would even pay attention to them. The real problem is what Cramer refers to as complacent bearishness. It is always so much easier to be publicly bearish than it is to be bullish in this market.

"The fact is, the most complacent people are the ones who presume that stocks that drop are finished and the market's swoons are all prologues to gigantic declines that must be sidestepped — or else," the "Mad Money" host said.

In fact, this year has been a series of roving bear markets, followed by thriving bull markets. One-by-one, each sector was taken down, regardless of the calendar. Oil, technology, retail, materials, biotech, consumer packaged goods. And with exception of retail, Cramer considered each sell-off to be a buying opportunity.

"If you were complacently bearish, like so many, you simply missed those opportunities. I know a lot of people who stayed on the sidelines when they should have been buying," Cramer said.

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That bearish sentiment in the market was evident to Cramer Wednesday. There was a decline in markets overseas, in part because the dollar was weak versus the euro. That European selling prompted the Dow Jones industrial average to drop 100 points at the open Thursday morning.

The overseas bearishness quickly floated over to the U.S., even though the weak dollar is a good thing for the U.S.

Another Thursday sign of bearishness was the OPEC meeting. It was clear that they would reach no agreement to raise the price of oil, which caused the price of crude to fall, and it took the with it. Cramer saw short-sellers everywhere.

In Cramer's opinion, investors who buy the stocks of high-quality companies when they are down are getting an opportunity. And that is an opportunity that could be missed by all of the innate complacent bearishness in the market.

"I don't want to scare you away from stocks when any kind of pullback can create some terrific buying opportunities. That strategy might not be alliterative, but I think it is right," Cramer said.

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