I came across this sentence while watching movie.
"We just never should've let you get mixed up in the damned thing."
I know that "should've" is used when I express the things i regret. So I think it's enough to just say that "We should've let you get mixed up in the damned thing.", but the actor didn't say above sentence. He added "never" in front of "should"
Is there any difference meaning between them? and also I'd like to know a role of "just" in that sentence.