Thomas the Tank Engine was the first object of his affection. A Beanie Baby he called Chito came next. In more recent years, Lego sets and Pokemon and Yu-Gi-Oh cards have caught his eye.

But no love has been as deep and abiding as his love for a sponge named Bob.

A.J. fell under the Sponge Spell two or so years ago, apparently while OD'ing on Nickelodeon at a friend's house.

Since then, it's been all sponge, all the time, with no signs of disenchantment.

His room, of course, is a shrine to his man, Bob. Books, toys, drawings and gadgets - including a pull-apart Bob, a la Mr. Potato Head - take up his shelves and litter his floor.

Open his drawers and you'll find a T-shirt and PJs. On top of his dresser is his prized (and prize-winning) Pinewood Derby entry, a chunk of wood transformed into a yellow sponge with wheels.

In the closet is last year's Halloween costume, in which he fashioned a box into FrankenSponge ScaryPants.

Over here, a SpongeBob visor, worn daily. Over there, a wristband, worn nearly every day. On the wall, a Bob poster.

The rest of the house has been Bobified, as well: In the kitchen, SB mac 'n' cheese. In the bathroom, Bob bandages. In the basement, stored since mid-summer, party invitations and supplies, all SB, for his December birthday.

At school, he told his new teacher yellow is his favorite color and he most wants to visit Los Angeles. ("Is there a beach there?" he asked me by way of explanation. Guess he thinks any place with water is likely to house a pineapple under the sea.)

Surely it was fate, then, that he walked away from a church raffle earlier this month with a huge box of SpongeBob stuff. Two bucks of raffle tickets; a lifetime of SB Post-It notes.

I must admit I don't really get it.

This is a boy who has never really bonded with the family dog and doesn't much care for the family guinea pig. He barely blinked when Stripe, his fish, took the final flush. His sisters are tolerated, though often not well. His dad and I are OK, but not as cool as you-know-who.

Add another SpongeBob to his collection, though, and he enters a deep-sea rapture, his eyes as bright and his smile as wide at his sea-faring hero.

I finally asked the kid why he likes SpongeBob so much.

"He's funny, hilarious," he answered earnestly, before describing each SpongeBob character, expounding on Bob's innate kindness, and reminding me again that the SpongeBob movie arrives at Thanksgiving.

Pressed, he plumbed deeper and hinted at some alter ego motivations.

"He's kind of just like me," he explained. "If he was shaped into like a real person, he'd kind of look like me, 'cause he has brown hair."

And gee, I thought having buck teeth was their common trait. (The hair, by the way, must be hidden in the Krusty Krab hat.)

As a mother, I suppose I should encourage a more suitable role model for my developing child. Maybe a president, astronaut, athlete or even his own father might be a good stand-in.

But, alas, his attachment to SpongeBob is more than a passing crush. He's too far gone into Bikini Bottom to resurface without his squishy, smiling pal.

And, hey, I'd rather he plaster his walls with pictures of a happy-go-lucky sponge than some jock-cum-criminal or cynical pol.

Who am I to separate a boy from his Bob?

E-mail patti@marriedwchildren.com