When Transportation Security Administration agents spotted three small knives in a passenger’s carry-on bag at Honolulu International Airport in January, they sent him back to check them. On his second trip through the scanners, they found the knives again — not-so-cleverly concealed inside a thermos. Nice try.

Who among us has not surrendered a tiny blade or three in our haste to catch a flight?

Since the Sept. 11, 2001, terrorist attacks, knives have been prohibited in airline cabins, along with box cutters, razor blades and all sorts of objects (snow globes? Play-Doh?) viewed by the TSA as potential weapons.

The TSA says it confiscates roughly 850 pounds of prohibited items each month at a typical large airport. About half that weight is knives.

The rest … well, more on that in a minute.

Beginning April 25, you’ll be free to bring aboard that mini Swiss Army knife, along with certain sporting goods that currently aren’t allowed. Collapsible knives with blades no longer than 2.36 inches and no wider than half an inch will be welcome, the TSA announced last week, along with ski poles, hockey sticks and golf clubs (but only two).

The immediate response from the flying public was a collective “Huh?”

“New TSA Rules Draw Praise of National Arbitrariness Association,” read the headline on comedian Andy Borowitz’s post on The New Yorker’s website. “‘We love that the list appears to have been put together with no organizing principle or logical system,’ said NAA executive director Carol Foyler. ‘It combines the virtues of making no sense and being impossible to remember.'”

Officially, the changes are meant to bring U.S. aviation safety rules in line with international standards. They also allow the TSA to focus on finding more dangerous items, such as explosives, instead of wasting time relieving passengers of corkscrews.

If the seeming randomness of baseball bats/no, golf clubs/yes only reinforces your suspicion that airport security exists mainly to hassle travelers, we direct you to the TSA blog, blog.tsa.gov, which provides a weekly accounting of the firearms, grenades, meat cleavers, cattle prods, blasting caps, fireworks, switchblades and other frightening items intercepted at checkpoints nationwide.

Last year, your fellow passengers tried to bring aboard 1,543 guns, almost 80 percent of them loaded, in their carry-ons.

The TSA “Week in Review” for March 1 reports 19 firearms — 17 of them loaded — and seven stun guns found in carry-on bags. In February, nine rounds of .45-caliber ammunition were found hidden under the handle of a roll-aboard suitcase, and knives were found concealed in an ink pen, a comb, the lining of a carry-on and a shoe.

Also in February, a passenger at Chicago’s Midway Airport tried to carry on a flare gun and four flares. “You know, if you want to signal a flight attendant, there is a little button above your head,” the blogger quipped, suggesting the TSA is not, after all, humorless.

Still, wisecrackers would do well to check out another regular blog feature, “What Not to Say at an Airport.”

Jan. 25, for example: “While preparing to go through the security lane, a passenger at Chicago O’Hare asked: ‘Should I remove my gun and bomb, too?'”

Back to the contraband: Three saw blades were found taped to the inside of an iPad case. A razor blade was found in the waistband of a pair of jeans. Nine ounces of black powder was found in a carry-on bag. A knife in a laptop, a saw blade in a shoe, a bladed multitool in a package of socks, a pistol in a potted plant, two guns in a bag of dirt. Yikes.

No, we don’t think everyone who tries to sneak a pocketknife aboard is plotting mayhem; more likely they didn’t check it because they’re avoiding the $25-per-bag fee. But nobody wants to fly with a grenade in the overhead bin. Thank God for those scanners.

So go ahead and keep your itty-bitty knife in your pocket. But please, check that other stuff, or leave it home. And be patient the next time you’re singled out for a search because something in your carry-on looks funny.

We happen to know that a gallon Ziploc full of Matchbox cars will get you pulled over 10 times out of 10. It’s nice to know someone’s paying attention.

Editorial by the Chicago Tribune