Though just why she does, I'm sure I don't know.
5 seconds sound clip from the Gone with the Wind (1939) movie soundboard.
You can hear this line at 03:16:18 in the Blu-ray version of the movie.
Quote context
[...]
- You're thinking that she's a fool for doing it, even if it did save your hide but
- Miss Melly's a fool, but not the kind you think.
- Though just why she does, I'm sure I don't know.
- If you weren't so drunk and insulting, I could explain everything. As it is, though...
- You get out of that chair once more...
- Of course, the comic figure in all this is the long-suffering Mr. Wilkes.
- Mr. Wilkes, who can't be mentally faithful to his wife and won't be unfaithful to her technically.
- Why doesn't he make up his mind?
[...]