Maybe by the time I'm 100, I'll figure out why . . .

* Most of the cabs you can catch at BWI Airport are SUVs. They are the most costly passenger cars to buy or operate. They are the least comfortable in the back seat. They are the most likely to tip over -- especially the way some of these guys drive. Wouldn't a boring sedan make more sense?

* You need to show a government-issued ID to buy a ticket on the MARC commuter train. But you can ride Metrorail or Metrobus -- both of which carry hundreds of times more passengers per day -- without flashing a license or a passport.

* TV executives have fallen so in love with the "crawl" (that procession of news headlines that march across the bottom of the screen). Much of the time, the crawl features trivia, or refried information. So when there's serious breaking news -- and not just a promo for the latest survivor TV show -- it'll be like the boy who cried wolf. The audience won't be paying attention.

* Medical science hasn't yet figured out a cure for "hat hair." I'll volunteer to be the first guinea pig. The other day, after three hours inside a baseball cap, I tried to brush my flowing locks. I looked like a grapefruit that had been squished inside a crate too long. So I poured a cup of water over my head and tried brushing again. I looked like a wet grapefruit that had been inside a crate too long. In a world that has given us machines that heat hair curlers, and gizmos that curl eyelashes with one pinch, can this be too much to ask?

* People grouse so bitterly about gas prices. They've risen only about 10 percent in the past six months. They're still well below the going rates in most of the rest of the world. And how hard is it to reduce one's driving when prices spike? If the average driver puts 350 miles a week on his car, it can't be that difficult to prune 35 of them.

* Great new colleges and universities aren't opening from sea to shining sea. It's fairly basic economics, gang. There's a surge in applicants (thanks to the baby boomlet). There's no way to get around the value of the product. There's a logjam at the gates of the 50 best institutions. So why doesn't someone open 50 additional schools? Like a bunch of venture capitalists, for instance?

* We don't provide gas allowances for police officers and firefighters who are too poor to live in the jurisdictions they serve. It's bad enough that they make less than half of what some first-year lawyers make. But to have to shell out an additional $20 a week for the privilege?

* Movie theaters don't hire ushers who enforce the rules -- and who have started to shave. A reader e-mailed me about an incident at a Georgetown movie theater a couple of weekends ago. A pack of 14-year-old boys amused themselves by fighting, throwing things and catcalling obscene comments throughout a feature film. When ticket-buyers complained, the usher said he'd call the manager. But the manager never showed. Why couldn't the usher handle the problem himself? Because he was a teenager himself, and he was obviously too scared.

* More people don't tip at car washes. When I recently dropped three bucks into the coffee can at my friendly scrubatorium on Georgia Avenue, I noticed all of 75 cents in the bottom. I asked one of the guys if they had already offloaded the can that morning. No, he said, 75 cents is about par for the course for each hour. For six guys! Get off your wallets, Washington.

* Metro accepted that ad from a radio station -- the one that screams, "TRAFFIC SUCKS" from dozens of bus backs. Yes, it snares your attention. Yes, it probably drives ears to that station. Yes, it's still a free country. Yes, thousands of people use the word "sucks," every day. But why does Metro have to make life any more coarse than it already is? What's next? A straight-out obscenity on the back of a bus?

* College sweatshirts cost so bloody much. In a campus bookstore the other day, I was momentarily tempted by an XL with a hood. Then I checked the price tag. Sixty-three bucks. Are college students really paying that much to have the name of a school on their chests? No wonder Mom and Dad are broke.

* Metrorail drivers can't give passengers a better heads-up as trains approach National Airport. There are two exits at that station, at opposite ends of the platform. If you don't know which to choose to reach a certain airline's ticket counter, you will tramp many needless steps. Yes, there are signs along the platform. But wouldn't it be nice to hear, as you're rising from your seat: "For US Airways, United and America West, exit toward the rear of the train. For all other carriers, exit toward the front"?

* Right-on-red is allowed in downtown Washington. It isn't just a matter of whether a right-on-redder can avoid oncoming vehicular traffic. It's also a matter of those strange two-legged beasts called pedestrians. Trust me, they tend to be quite common downtown -- and they've been taught that a WALK sign gives them the right of way. How many times has a right-on- redder screeched around a corner, narrowly missing a thigh?

* Parents give toddlers something to eat as soon as the kiddos emit a peep of discontent. This way lies a 250-pound adult. How about talking to the child? Playing with the child? Reading to the child?

* Groceries don't make the obvious leap and get into the restaurant business -- right there among the dust mops and doughnuts. Food is an impulse business. Why not entice customers once you've got them -- and once they're salivating anyway? Hey, if the airlines are going to offer food for sale while a captive audience is flying . . . . And who could ever wonder about the way airlines do business?