Matthew Perry has always been candid about his struggles with substance abuse over the course of his career, and especially during his time on "Friends." And he's not changing that policy now, like he was when asked by a BBC Radio 2 interviewer what his least favorite "Friends" episode is. It turns out, that's kind of a tough one.

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"Oh my goodness," says Perry, who is in London for a new play, "The End of Longing," opening next month. "I think the answer is I don't remember three years of it. So none of those ... somewhere between Season 3 and 6. A little bit of the time, I was a little out of it, yeah." 

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Good news for Perry, though: Every episode of "Friends" is available to stream on Netflix, so he can totally do a binge-watch and refresh his memory. Wait, should I not have used the word "binge"?

Follow Ned Ehrbar on Twitter: @nedrick