A puzzle

It is a conundrum, a puzzle, and it is very difficult to solve, but you're probably smart enough.

Here is the set up:

We work in tandem, a bunch of clerks, pages, whatever you call us. One of us works in one place for an hour or two, and then another of us comes along to replace the first. Some of these jobs are very diffuse. You arrive to do the job and it is impossible to tell if the person working there before you has been working very hard or has hardly been working at all. Some jobs are mostly at the whim of whatever comes to you at the time you are there. At the front desk, for instance, you are either busy or not, and it is beyond your control. But some jobs are very specific. Some jobs have very measurable work. There were two full bins here at the start of the hour, now there are none.

Here is the puzzling scenario:

The person before you, at the station you will be going to work at, has two bins. If they work very hard they will get both bins done. If they poke around on the Internet, and sit around chatting, and generally just do their own thing, they will get close to nothing done. If that person does the work and finishes the two bins, then, really, the fair thing is that when it's your turn you step up and work pretty hard too. They have set a standard worth living up to. It is time to step up to this high standard! The only problem is that now there is no work to do! On the other hand, if they have lazed about the whole time that they were over there, sitting around with all those still full bins, then, well, that's pretty disrespectful to you, and the whole stupid place you work at is falling apart anyway, and the hell with it, don't you deserve a little downtime? You do. You do deserve downtime! So you might as well do nothing. The only problem is that you're now totally backed up, and you really need to get to work, which is really too unfair for words.

In short: When it is right and good for you to work hard there is nothing much to do, and when you richly deserve to take it easy you are swamped.
 
Fortunately, as these are the two extremes, I am only faced with this terrible puzzle occasionally. There is, of course, one solution to it, and I am guessing you have already smoked it out:

You march right into your supervisors office, and you say, without equivocation or hesitation, "I have a terrible headache. I think I'd better go home."

And then you do.