Interactively search through bash history with CTRL+R

Let's say you want to reuse a command you typed a couple of hours/days ago.

There is a better way than :
history | grep the_command_I_always_forget
(Or worst hitting the up key till you finally reach the command you are looking for)

Just hit :
CTRL+R
Start typing a few letters of the command you are looking for and let magic happen !