Every f**king time

Press "k" instead. Go, go try it.

WTF are you using?

First world problems

Sounds like you've been using VLC.

Use the "k" key. As long as you are on a youtube page, it will pause/unpause. "J" and "L" will move backward and forward 10 seconds, respectively.

It'll work as long as the video is that last thing you clicked on.
Also, what graffyn_guy said.

PREACH!!!

Use j, k, and l. K pauses, and j and l go forward and back respectively

or when it loads again a part that was already loaded

Or, skip ahead and it restarts.