I think you and a lot of other people as well; and smart phones don't help as you point out.
I don't have that issue myself and can be quite disciplined when it comes to getting things done. I schedule time for certain things, researching a vehicle for instance, and when the time elapsed I'm done and move on to whatever's next. It probably sounds quite regimented putting it that way, it's not really, just that I like to make the most of my time and blocking out time for things helps.
I like what you said about turning off notifications, I do the same.