The lesson being, if you ever start a sentence by sneering “the last time I checked,” you probably should have actually checked:

Mayor Bloomberg Friday interrupted a radio health care discussion to blurt out that drug companies — and their execs — don’t make big bucks.

“Last time I checked, pharmaceutical companies don’t make a lot of money,” he said on his WOR-AM radio show. “Their executives don’t make a lot of money.”

Someone must have quickly rechecked, because he backpedaled after a commercial break.

“I looked up the top pay of some of these executives in big pharma,” Bloomberg said.

“Some of them are making a lot of money. Some of them are making a decent amount of — more than a decent amount of money.”

Corollary: Voters probably don’t care about what you think about R&D costs . . .