I use this activity when the students first encounter the verb "was" in junior high.
First I communicate to the class that all of their teachers were once junior high school students just like them. Next I pass out the worksheet and review the 8 types of students with the class. I check to make sure they understand each and introduce words like "delinquent" (which is a bit of an awkward word but I'm not sure what word would be better).
Then I demonstrate the general pattern with the JTE. "What was (this class' homeroom teacher) when he/she was a junior high school student?" "He/She was a..." I find that the students get a kick out of teachers that seem to have some kind of idiosyncrasies - maybe they like one sport or particular or have a certain kind of personality. After the students have the gist of that, I ask them to choose one teacher at their school and write it on the question line up at the top. Then students need to ask other students what they think that teacher was like back in the day. Of course it's okay to give answers outside of the listed ones, but hopefully they give some ideas to the students. Feel free to alter those to your circumstances, of course!