(See below)

I've become addicted to footnotes --- yet another fallout of thesis-writing.

Item #16 on the "You might be a grad student if..." list, from the Facebook group, "Grad Students: they're Not Bad People, they Just Made Terrible Life Choices":

...you get irresistible urges to use in-text citations in casual e-mails.

See the second entry in this blog, for example. :P