老友记第一季第一集had that dream怎么理解~

老友记第一季第一集had that dream怎么理解~
钱德说他高中的时候,裸体站在食堂里.后面众人说了一句 Had that dream.后来乔伊又说了一句Never had that dream,要怎么理解阿?
剧本复制如下
Chandler:Alright,so I'm back in high school,I'm standing in the middle of the cafeteria,and I realize I am totally naked.
All:Oh,yeah.Had that dream.
Chandler:Then I look down,and I realize there's a phone...there.
Joey:Instead of...
Chandler:That's right.
Joey:Never had that dream.