This has been bothering me for a while, almost every repo I’d check out had changes that I couldn’t discard. Long story short, I tried all of the above, nothing worked. This is what I did to get things back to normal (on a Mac):
Completely remove the autocrlf & safecrlf settings from ~/.gitconfig
Completely remove the autocrlf & safecrlf settings from your repo's local config ./.git/config
git rm --cached -r .
git reset --hard