Knowing a lecturer from a previous course of study, would it have an impact?
Anybody who has taught and likes teaching knows that one of the biggest rewards is seeing your students grow.  From your description, it sounds like your only problems in your previous encounter were age-typical lack of focus and brattiness. If you are now a much more mature and polished student, then more likely than not, if the lecturer remembers you at all, it will be to your advantage when they compare with the kid they taught so many years ago.