Yes, I really needed to completely block Youtube via hosts. Though it's true that you DO sometimes actually really need to watch a youtube video. That's why I have my crappy old laptop available as well. It's there, but it's definitely not smooth experience.

I'm not good about asking myself whether watching a video is really a good use of my time. It's the impulse of the moment, it's just a click away, and it just happens. 

That's why I have the "default" setting of no internet, and internet actually turning off every hour. I have to manually go and turn it on, and that little action (hopefully) will make me think more carefully.

It's all about adding friction...

Signal312

The last bullet seems like the big one. I still probably spend too much time on YouTube, although I've gotten pretty good about asking myself if I really want to watch a video before clicking on it and I often don't watch anything.