What's the name of this t.v. show?

I remember my 8th grade teacher showed us a part of a t.v. show.
I don't remember much about it. But apparently she was a big bitch,
and then she got into some sort of accident and forgot all of her
memory and became a good person afterwords. and through the show she
has flashbacks of her life. So please help! what's the name of this
show? :)

Thank you!