Once upon a time, I could have sworn that find-file completion had a feature whereby if the first character you typed was a / or a ~, the entire default directory was erased and replaced with the / or ~.  This was terribly convenient.

Right now, if you want to open an absolute file name (or one relative to your home directory), you have to hit C-a C-k after you type C-x C-f and before you type / or ~.  Annoying.

Did I dream this feature?  Did it go away?  How can I make find-file behave this way again?

Thanks,
Eric