I will probably get on your nerves as your cubicle neighbor at work because:

1. When I think hard about a problem, I do the click-a-click thing with my pen. And then I realize that I'm doing it and that it probably annoys you, so I stop it. And then I start doing it again as I begin to think hard again. Over and over. For the rest of times.
2. When I walk out of my cubicle, I sigh. Almost every time. For no reason. Other than the fact that, clearly, getting out of my chair drains the life out of me.