Y'all know it, sometimes you mess up typing in the shell. It happens. Luckily there's a pretty neat way to call specific arguments from a previous command, and I'm gonna write about one way.
Imagine that you do this:
$ cd ~/Documents/so/many/nested/folders/file.txt
You know you can't cd into a file. You meant to open that in Atom. But "aww man, I don't want to type that path again and I'm too lazy to be bothered to do anything else". Don't fear!
!!$ is here.
Instead of retyping all that, just type:
$ atom !!$
What this does is runs a command against the first argument in the last command you ran. Nifty!