Heh, no problem here are 2 more bang tricks. !<charachters> runs the last command you ran that starts with the characters you type.

  !gre      # will run the last command starting with gre (so probably grep)

If you type history, then !<number to the left of the history command>, the shell will execute that command.

  $ history # shows command history
  $ !200    # executes command 200