Now that a rehabbed Colin Farrell is sober and on the mend (and has put on some pounds since his "homeless dude outside Trader Joe's" days), it's time for him to pull a Britney and wonder aloud, "What the hell was I thinking?" Naturally, any investigation of his substance-aided antics would inevitably turn to the sex tape he made with Playmate Nicole Narain, and during a recent BBC appearance, Farrell attempted to explain away the indiscretion the best way he knew how.What made the actor shout "I FUCKING LIVE ON PORN!" and "Aw, the battery's dead...so is my fucking cock" while copulating in a depressing Valley one-bedroom? The answer, it may not surprise you to hear, was that he was totally high and turned on by the taboo of the camera. Still, Farrell claims that he has learned one valuable lesson: it's fine to make a sex tape, just don't leave it behind when you straggle out to the Albertson's on Ventura at 5am for a Hot Pocket and some lube.