[TMWNN]

Perry would look very, very different on Friends between the last episode of a season and the first episode of the next, because he would go through rehab. Especially noticeable when watching reruns when the episodes are connected with a cliffhanger.

[Fezzik]

In one of his recent interviews for his book tour he talked about how could not now watch Friends because, based on how looked in the particular season, he would immediately remember what drug he was struggling with - pills, cocaine, or alcohol.

[TMWNN]

That's horrible to hear. Reminds me of Stephen King. From Wikipedia:

>Stephen King discusses Cujo in On Writing, referring to it as a novel he "barely remembers writing at all." King wrote the book during the height of his struggle with alcohol addiction. King goes on to say he likes the book and wishes he could remember enjoying the good parts as he put them on the page.

I imagine that Perry probably could not remember filming many episodes/scenes.