I guess almost everyone will agree on that line. Whenever you have plenty of things to do, you find less and less time to do those things. You keep doing one thing, and then suddenly, day ends, month ends, year ends, and you wonder, what the hell happened? where the hell has all the time gone? I am still to do so and so things. But that's what happens, and that's how life goes.
I know many people will be eager to give advice on planning, timetables, etc. etc. That works only to some extent. Anybody says more about managing work, that's all bullshit. Come on, show me a person for whom everything goes according to plan. I believe people for whom plans work perfectly, either they are horribly unambitious about what they can achieve or they are extremely lucky. I know, I know that planning is about being prepared but hell, but just being prepared doesn't get things done, you actually have to do the things.