Forgive me, Simpsons, but I don't watch you as often as I used to. I'm not sure when it happened, but at some point, watching The Simpsons slipped from an every-week ritual to catch as catch can.

I'm sure I'm not unusual in that respect. I'm sure there are people who were with The Simpsons from those very first shaky frames, who saw them adopt No. 9 and laughed at Homer botching Christmas songs on the closing credits, and faithfully watched for several years, maybe even a decade before they dropped off.

But one of the best things about the show is, you can always come back. The Simpsons never forget. Yesterday's episode and the 20th Anniversary Special that followed was a nice reminder of that. The episode wasn't the funniest I've seen, but I did realize there has never been an episode of the show that wasn't worth at least a few laughs.

The jokes are stuffed everywhere, starting with the opening sequence, which yesterday featured Marge reading Anxious Mother magazine with an "Absolut Krusty" ad on the back in the grocery line (other titles: Peephole and Donut Fancy) and the self-referential billboard ("The Fox Network: Still Sucking After 20 Years") and Bart's chalkboard ("The World May End in 2012 But This Show Won't"). And I like the idea of Gary Larson drawing cartoons somewhere exclusively for a bunch of working stiffs at a power plant.

Which is another enjoyable thing about The Simpsons - the guest voices. Gary Larson actually played himself, which marked the first time I've actually heard the man's voice after decades of enjoying The Far Side. Also lending their voices were Anne Hathaway, the late Eartha Kitt (who was actually referred to as such in the dialogue), Jackie Mason, and Maurice Lamarche (of Futurama, Egon Spengler of The Real Ghostbusters, and The Brain of Pinky and the Brain).

Morgan Spurlock's documentary showed The Simpsons showing up around the world, upsetting people at the Catholic League, and even being used as a whipping boy by the senior George Bush. In college, I brought up the episode where Bart sells his soul in my Marlowe class, and the professor countered by talking about Flanders as the devil. And there are a dozen or so episodes that are never far from regular reference for me ("Donuts, is there anything they can't do?"). So I feel somewhat guilty I don't watch every week anymore.

This week's show ended on a wistful, romantic note, thanking fans for their two years of viewership and promising "the best is yet to come." That's a pretty tall order. But enough people are watching to keep the show around, and I'm thankful for that. Simpsons, may you stay on the air until hell runs out of donuts.