!n
The command numbered n in history, called by its number.
Every line in history has a number, and history shows them all. !1337 re-runs line 1337, no matter how long ago it was typed.
Useful for revisiting long sessions: run history, find the line, call it by number. Just don't memorize numbers across sessions — they drift as history grows.
$ history | tail -3
1336 cd ~/coleta
1337 ./prensar.sh --tudo
1338 history | tail -3
$ !1337
./prensar.sh --tudo