In the film Johnny English Strikes Again, Bough asks Johnny English: "Is it true you were teaching, sir?" (26min52sec) He means that Johnny English was a teacher before their current mission. This usage of past continuous is somewhat unknown to me. I always hear that past continuous is used when referring to a certain moment ("I was sleeping when..."). Could anyone please explain why is it so, as opposed to "you taught", and give some other similar examples of past continuous without referring to a certain moment? Thank you.

the film:



Other examples of this type of past continuous usage:

A: I met my husband at Berkeley.

B: But he's 30 yrs. older than you.

A: I was taking an undergrad course in quantum mechanics and he was the professor.

C: I met my wife in Africa.

D: What were you doing in Africa?

C: I was teaching in a mission school in Uganda and she was a relief worker in the same area.

After a Dear John letter and numerous hang ups when I called her, I was beginning to see the light: she just wasn't interested in me.