DaveWatch: Countdown to Letterman's Last 'Late Show,' Day 22

Paul Rudd goes fanboy and a sponge steals the show as the Letterman farewell tour continues

Paul Rudd and David Letterman on the 'Late Show with David Letterman.'

"I know how much you hate compliments," Paul Rudd said to David Letterman, as the future Ant-Man made his last Late Show appearance. "So it must be hard, now that everyone wants to tell you what you mean [to them]."

Indeed, the whole final-month-of-shows thing has to be fairly tough going for our Dave; doing a farewell tour from your own desk is surreal enough, but there are times when it must feel a little like being a guest at your own wake. Last night's episode began in energetic enough fashion, with Paul Shaffer and band providing JB's-style punctuation to Letterman's movements, and the studio audience greeting his arrival with what appeared to be a spontaneous standing ovation. ("Okay, that's plenty," he grumbled playfully. "What, do you just need the exercise?")

But for much of the show, Dave seemed content to lose himself in minutiae like last night's Top 10 list ("Top 10 Things Overheard at the Latest Secret Service Meeting"), or let pre-recorded segments like "Meet Bernie Sanders" or the spot-on Shawshank Redemption spoof from 2006 do the heavy comedic lifting. In fact, he seemed distracted by the time Rudd took the guest chair, and their conversation began in less-than-promising fashion: "How are you doing?" the This Is 40 actor asked, to which Dave followed up with a rather unconvincing "Uh… I'm okay." After some flat discourse regarding the Kansas City Royals' trip to the 2014 World Series (which was only, like, jeez, six months ago), the host perked right up once Rudd revealed that he'd once been a member of an unauthorized David Letterman Fan Club in his youth — causing Dave to chuckle at the memory of having to "send them a cease and desist order."

Rudd brought some of the old group's swag with him, including a David Letterman pin, and a special David Letterman sponge. ("And you're saying it was a lousy fan club?" the host cackled.) The three decades-old sponge, which sported the instructions "DIP IN WATER — SEE WHAT HAPPENS," finally received its inaugural bath in a bowl on Dave's desk, and the "pyrotechnics" that followed (cue the band played "Also Sprach Zarathustra") came off like a miniature reprise of the "Human Sponge Suit" from the Eighties' shows.

Unauthorized though it may have been, that sponge was the funniest — and the most quintessentially "Letterman" — thing on last night's show, and the twinkle in Dave's eyes seemed to say, "If this is the kind of thing I'm going to be remembered for, then it was all truly worth it." Hopefully, we'll be seeing a lot more of that twinkle over the next few weeks.