If you have typed in
Man I was mean, but I'm changing my scene
And then press
alt shift b (the shift may not be needed) twice the cursor will go back to the
alt shift f moves in the opposite direction, incidentally)
alt shift d it will delete the word
my. Press it again and it will then delete
ctl d and you will delete not the word but a single character under the cursor.
ctl k and you will delete everything after the position.
ctl u everything before.
ctl _ and you will undo your command line edits.